实例详解Android快速开发工具类总结

一、日志工具类 log.java

public class l 
{ 
private l() 
{ 
/* 不可被实例化 */ 
throw new unsupportedoperationexception("cannot be instantiated!"); 
} 
// 是否需要打印bug，可以在application的oncreate函数里面初始化 
public static boolean isdebug = true; 
private static final string tag = "defaulttag"; 
// 下面四个是默认tag的函数 
public static void i(string msg) 
{ 
if (isdebug) 
log.i(tag, msg); 
} 
public static void d(string msg) 
{ 
if (isdebug) 
log.d(tag, msg); 
} 
public static void e(string msg) 
{ 
if (isdebug) 
log.e(tag, msg); 
} 
public static void v(string msg) 
{ 
if (isdebug) 
log.v(tag, msg); 
} 
// 下面是传入自定义tag的函数 
public static void i(string tag, string msg) 
{ 
if (isdebug) 
log.i(tag, msg); 
} 
public static void d(string tag, string msg) 
{ 
if (isdebug) 
log.i(tag, msg); 
} 
public static void e(string tag, string msg) 
{ 
if (isdebug) 
log.i(tag, msg); 
} 
public static void v(string tag, string msg) 
{ 
if (isdebug) 
log.i(tag, msg); 
} 
}

二、toast统一管理类 tost.java

public class t 
{ 
private t() 
{ 
/* cannot be instantiated */ 
throw new unsupportedoperationexception("cannot be instantiated"); 
} 
public static boolean isshow = true; 
/** 
* 短时间显示toast 
*/ 
public static void showshort(context context, charsequence message) 
{ 
if (isshow) 
toast.maketext(context, message, toast.length_short).show(); 
} 
/** 
* 短时间显示toast 
* @param message 要显示的字符串资源的id
*/ 
public static void showshort(context context, int message) 
{ 
if (isshow) 
toast.maketext(context, message, toast.length_short).show(); 
} 
/** 
* 长时间显示toast 
*/ 
public static void showlong(context context, charsequence message) 
{ 
if (isshow) 
toast.maketext(context, message, toast.length_long).show(); 
} 
/** 
* 长时间显示toast 
*/ 
public static void showlong(context context, int message) 
{ 
if (isshow) 
toast.maketext(context, message, toast.length_long).show(); 
} 
/** 
* 自定义显示toast时间 
*/ 
public static void show(context context, charsequence message, int duration) 
{ 
if (isshow) 
toast.maketext(context, message, duration).show(); 
} 
/** 
* 自定义显示toast时间 
*/ 
public static void show(context context, int message, int duration) 
{ 
if (isshow) 
toast.maketext(context, message, duration).show(); 
} 
}

三、sharedpreferences封装类 sputils.java 和 preferencesutils.java

1. sputils.java

public class sputils 
{ 
/** 
* 保存在手机里面的文件名 
*/ 
public static final string file_name = "share_data"; 
/** 
* 保存数据的方法，我们需要拿到保存数据的具体类型，然后根据类型调用不同的保存方法 
* 
* @param context 
* @param key 
* @param object 
*/ 
public static void put(context context, string key, object object) 
{ 
sharedpreferences sp = context.getsharedpreferences(file_name, 
context.mode_private); 
sharedpreferences.editor editor = sp.edit(); 
if (object instanceof string) 
{ 
editor.putstring(key, (string) object); 
} else if (object instanceof integer) 
{ 
editor.putint(key, (integer) object); 
} else if (object instanceof boolean) 
{ 
editor.putboolean(key, (boolean) object); 
} else if (object instanceof float) 
{ 
editor.putfloat(key, (float) object); 
} else if (object instanceof long) 
{ 
editor.putlong(key, (long) object); 
} else 
{ 
editor.putstring(key, object.tostring()); 
} 
sharedpreferencescompat.apply(editor); 
} 
/** 
* 得到保存数据的方法，我们根据默认值得到保存的数据的具体类型，然后调用相对于的方法获取值 
* 
* @param context 
* @param key 
* @param defaultobject 
* @return 
*/ 
public static object get(context context, string key, object defaultobject) 
{ 
sharedpreferences sp = context.getsharedpreferences(file_name, 
context.mode_private); 
if (defaultobject instanceof string) 
{ 
return sp.getstring(key, (string) defaultobject); 
} else if (defaultobject instanceof integer) 
{ 
return sp.getint(key, (integer) defaultobject); 
} else if (defaultobject instanceof boolean) 
{ 
return sp.getboolean(key, (boolean) defaultobject); 
} else if (defaultobject instanceof float) 
{ 
return sp.getfloat(key, (float) defaultobject); 
} else if (defaultobject instanceof long) 
{ 
return sp.getlong(key, (long) defaultobject); 
} 
return null; 
} 
/** 
* 移除某个key值已经对应的值 
* @param context 
* @param key 
*/ 
public static void remove(context context, string key) 
{ 
sharedpreferences sp = context.getsharedpreferences(file_name, 
context.mode_private); 
sharedpreferences.editor editor = sp.edit(); 
editor.remove(key); 
sharedpreferencescompat.apply(editor); 
} 
/** 
* 清除所有数据 
* @param context 
*/ 
public static void clear(context context) 
{ 
sharedpreferences sp = context.getsharedpreferences(file_name, 
context.mode_private); 
sharedpreferences.editor editor = sp.edit(); 
editor.clear(); 
sharedpreferencescompat.apply(editor); 
} 
/** 
* 查询某个key是否已经存在 
* @param context 
* @param key 
* @return 
*/ 
public static boolean contains(context context, string key) 
{ 
sharedpreferences sp = context.getsharedpreferences(file_name, 
context.mode_private); 
return sp.contains(key); 
} 
/** 
* 返回所有的键值对 
* 
* @param context 
* @return 
*/ 
public static map<string, ?> getall(context context) 
{ 
sharedpreferences sp = context.getsharedpreferences(file_name, 
context.mode_private); 
return sp.getall(); 
} 
/** 
* 创建一个解决sharedpreferencescompat.apply方法的一个兼容类 
* 
* @author zhy 
* 
*/ 
private static class sharedpreferencescompat 
{ 
private static final method sapplymethod = findapplymethod(); 
/** 
* 反射查找apply的方法 
* 
* @return 
*/ 
@suppresswarnings({ "unchecked", "rawtypes" }) 
private static method findapplymethod() 
{ 
try 
{ 
class clz = sharedpreferences.editor.class; 
return clz.getmethod("apply"); 
} catch (nosuchmethodexception e) 
{ 
} 
return null; 
} 
/** 
* 如果找到则使用apply执行，否则使用commit 
* 
* @param editor 
*/ 
public static void apply(sharedpreferences.editor editor) 
{ 
try 
{ 
if (sapplymethod != null) 
{ 
sapplymethod.invoke(editor); 
return; 
} 
} catch (illegalargumentexception e) 
{ 
} catch (illegalaccessexception e) 
{ 
} catch (invocationtargetexception e) 
{ 
} 
editor.commit(); 
} 
} 
}

对sharedpreference的使用做了建议的封装，对外公布出put，get，remove，clear等等方法；

注意一点，里面所有的commit操作使用了sharedpreferencescompat.apply进行了替代，目的是尽可能的使用apply代替commit.
首先说下为什么，因为commit方法是同步的，并且我们很多时候的commit操作都是ui线程中，毕竟是io操作，尽可能异步；
所以我们使用apply进行替代，apply异步的进行写入；
但是apply相当于commit来说是new api呢，为了更好的兼容，我们做了适配；
sharedpreferencescompat也可以给大家创建兼容类提供了一定的参考

2. sputils.java

public class preferencesutils {
public static string preference_name = "trineaandroidcommon";
private preferencesutils() {
throw new assertionerror();
}
/**
* put string preferences
* 
* @param context
* @param key the name of the preference to modify
* @param value the new value for the preference
* @return true if the new values were successfully written to persistent storage.
*/
public static boolean putstring(context context, string key, string value) {
sharedpreferences settings = context.getsharedpreferences(preference_name, context.mode_private);
sharedpreferences.editor editor = settings.edit();
editor.putstring(key, value);
return editor.commit();
}
/**
* get string preferences
* 
* @param context
* @param key the name of the preference to retrieve
* @return the preference value if it exists, or null. throws classcastexception if there is a preference with this
* name that is not a string
* @see #getstring(context, string, string)
*/
public static string getstring(context context, string key) {
return getstring(context, key, null);
}
/**
* get string preferences
* 
* @param context
* @param key the name of the preference to retrieve
* @param defaultvalue value to return if this preference does not exist
* @return the preference value if it exists, or defvalue. throws classcastexception if there is a preference with
* this name that is not a string
*/
public static string getstring(context context, string key, string defaultvalue) {
sharedpreferences settings = context.getsharedpreferences(preference_name, context.mode_private);
return settings.getstring(key, defaultvalue);
}
/**
* put int preferences
* 
* @param context
* @param key the name of the preference to modify
* @param value the new value for the preference
* @return true if the new values were successfully written to persistent storage.
*/
public static boolean putint(context context, string key, int value) {
sharedpreferences settings = context.getsharedpreferences(preference_name, context.mode_private);
sharedpreferences.editor editor = settings.edit();
editor.putint(key, value);
return editor.commit();
}
/**
* get int preferences
* 
* @param context
* @param key the name of the preference to retrieve
* @return the preference value if it exists, or -. throws classcastexception if there is a preference with this
* name that is not a int
* @see #getint(context, string, int)
*/
public static int getint(context context, string key) {
return getint(context, key, -);
}
/**
* get int preferences
* 
* @param context
* @param key the name of the preference to retrieve
* @param defaultvalue value to return if this preference does not exist
* @return the preference value if it exists, or defvalue. throws classcastexception if there is a preference with
* this name that is not a int
*/
public static int getint(context context, string key, int defaultvalue) {
sharedpreferences settings = context.getsharedpreferences(preference_name, context.mode_private);
return settings.getint(key, defaultvalue);
}
/**
* put long preferences
* 
* @param context
* @param key the name of the preference to modify
* @param value the new value for the preference
* @return true if the new values were successfully written to persistent storage.
*/
public static boolean putlong(context context, string key, long value) {
sharedpreferences settings = context.getsharedpreferences(preference_name, context.mode_private);
sharedpreferences.editor editor = settings.edit();
editor.putlong(key, value);
return editor.commit();
}
/**
* get long preferences
* 
* @param context
* @param key the name of the preference to retrieve
* @return the preference value if it exists, or -. throws classcastexception if there is a preference with this
* name that is not a long
* @see #getlong(context, string, long)
*/
public static long getlong(context context, string key) {
return getlong(context, key, -);
}
/**
* get long preferences
* 
* @param context
* @param key the name of the preference to retrieve
* @param defaultvalue value to return if this preference does not exist
* @return the preference value if it exists, or defvalue. throws classcastexception if there is a preference with
* this name that is not a long
*/
public static long getlong(context context, string key, long defaultvalue) {
sharedpreferences settings = context.getsharedpreferences(preference_name, context.mode_private);
return settings.getlong(key, defaultvalue);
}
/**
* put float preferences
* 
* @param context
* @param key the name of the preference to modify
* @param value the new value for the preference
* @return true if the new values were successfully written to persistent storage.
*/
public static boolean putfloat(context context, string key, float value) {
sharedpreferences settings = context.getsharedpreferences(preference_name, context.mode_private);
sharedpreferences.editor editor = settings.edit();
editor.putfloat(key, value);
return editor.commit();
}
/**
* get float preferences
* 
* @param context
* @param key the name of the preference to retrieve
* @return the preference value if it exists, or -. throws classcastexception if there is a preference with this
* name that is not a float
* @see #getfloat(context, string, float)
*/
public static float getfloat(context context, string key) {
return getfloat(context, key, -);
}
/**
* get float preferences
* 
* @param context
* @param key the name of the preference to retrieve
* @param defaultvalue value to return if this preference does not exist
* @return the preference value if it exists, or defvalue. throws classcastexception if there is a preference with
* this name that is not a float
*/
public static float getfloat(context context, string key, float defaultvalue) {
sharedpreferences settings = context.getsharedpreferences(preference_name, context.mode_private);
return settings.getfloat(key, defaultvalue);
}
/**
* put boolean preferences
* 
* @param context
* @param key the name of the preference to modify
* @param value the new value for the preference
* @return true if the new values were successfully written to persistent storage.
*/
public static boolean putboolean(context context, string key, boolean value) {
sharedpreferences settings = context.getsharedpreferences(preference_name, context.mode_private);
sharedpreferences.editor editor = settings.edit();
editor.putboolean(key, value);
return editor.commit();
}
/**
* get boolean preferences, default is false
* 
* @param context
* @param key the name of the preference to retrieve
* @return the preference value if it exists, or false. throws classcastexception if there is a preference with this
* name that is not a boolean
* @see #getboolean(context, string, boolean)
*/
public static boolean getboolean(context context, string key) {
return getboolean(context, key, false);
}
/**
* get boolean preferences
* 
* @param context
* @param key the name of the preference to retrieve
* @param defaultvalue value to return if this preference does not exist
* @return the preference value if it exists, or defvalue. throws classcastexception if there is a preference with
* this name that is not a boolean
*/
public static boolean getboolean(context context, string key, boolean defaultvalue) {
sharedpreferences settings = context.getsharedpreferences(preference_name, context.mode_private);
return settings.getboolean(key, defaultvalue);
}
}

四、单位转换类 densityutils.java

public class densityutils 
{ 
private densityutils() 
{ 
/* cannot be instantiated */ 
throw new unsupportedoperationexception("cannot be instantiated"); 
} 
/** 
* dp转px 
* 
* @param context 
* @param val 
* @return 
*/ 
public static int dppx(context context, float dpval) 
{ 
return (int) typedvalue.applydimension(typedvalue.complex_unit_dip, 
dpval, context.getresources().getdisplaymetrics()); 
} 
/** 
* sp转px 
* 
* @param context 
* @param val 
* @return 
*/ 
public static int sppx(context context, float spval) 
{ 
return (int) typedvalue.applydimension(typedvalue.complex_unit_sp, 
spval, context.getresources().getdisplaymetrics()); 
} 
/** 
* px转dp 
* 
* @param context 
* @param pxval 
* @return 
*/ 
public static float pxdp(context context, float pxval) 
{ 
final float scale = context.getresources().getdisplaymetrics().density; 
return (pxval / scale); 
} 
/** 
* px转sp 
* 
* @param fontscale 
* @param pxval 
* @return 
*/ 
public static float pxsp(context context, float pxval) 
{ 
return (pxval / context.getresources().getdisplaymetrics().scaleddensity); 
} 
}

typedvalue：

container for a dynamically typed data value. primarily used with resources for holding resource values.
applydimension(int unit, float value, displaymetrics metrics)：
converts an unpacked complex data value holding a dimension to its final floating point value.

五、sd卡相关辅助类 sdcardutils.java

public class sdcardutils 
{ 
private sdcardutils() 
{ 
/* cannot be instantiated */ 
throw new unsupportedoperationexception("cannot be instantiated"); 
} 
/** 
* 判断sdcard是否可用 
* 
* @return 
*/ 
public static boolean issdcardenable() 
{ 
return environment.getexternalstoragestate().equals( 
environment.media_mounted); 
} 
/** 
* 获取sd卡路径 
* 
* @return 
*/ 
public static string getsdcardpath() 
{ 
return environment.getexternalstoragedirectory().getabsolutepath() 
+ file.separator; 
} 
/** 
* 获取sd卡的剩余容量 单位byte 
* 
* @return 
*/ 
public static long getsdcardallsize() 
{ 
if (issdcardenable()) 
{ 
statfs stat = new statfs(getsdcardpath()); 
// 获取空闲的数据块的数量 
long availableblocks = (long) stat.getavailableblocks() - ; 
// 获取单个数据块的大小（byte） 
long freeblocks = stat.getavailableblocks(); 
return freeblocks * availableblocks; 
} 
return ; 
} 
/** 
* 获取指定路径所在空间的剩余可用容量字节数，单位byte 
* 
* @param filepath 
* @return 容量字节 sdcard可用空间，内部存储可用空间 
*/ 
public static long getfreebytes(string filepath) 
{ 
// 如果是sd卡的下的路径，则获取sd卡可用容量 
if (filepath.startswith(getsdcardpath())) 
{ 
filepath = getsdcardpath(); 
} else 
{// 如果是内部存储的路径，则获取内存存储的可用容量 
filepath = environment.getdatadirectory().getabsolutepath(); 
} 
statfs stat = new statfs(filepath); 
long availableblocks = (long) stat.getavailableblocks() - ; 
return stat.getblocksize() * availableblocks; 
} 
/** 
* 获取系统存储路径 
* 
* @return 
*/ 
public static string getrootdirectorypath() 
{ 
return environment.getrootdirectory().getabsolutepath(); 
} 
}

statfs 是android提供的一个类：

retrieve overall information about the space on a filesystem. this is a wrapper for unix statvfs().

检索一个文件系统的整体信息空间。这是一个unix statvfs() 包装器

六、屏幕相关辅助类 screenutils.java

public class screenutils 
{ 
private screenutils() 
{ 
/* cannot be instantiated */ 
throw new unsupportedoperationexception("cannot be instantiated"); 
} 
/** 
* 获得屏幕高度 
* 
* @param context 
* @return 
*/ 
public static int getscreenwidth(context context) 
{ 
windowmanager wm = (windowmanager) context 
.getsystemservice(context.window_service); 
displaymetrics outmetrics = new displaymetrics(); 
wm.getdefaultdisplay().getmetrics(outmetrics); 
return outmetrics.widthpixels; 
} 
/** 
* 获得屏幕宽度 
* 
* @param context 
* @return 
*/ 
public static int getscreenheight(context context) 
{ 
windowmanager wm = (windowmanager) context 
.getsystemservice(context.window_service); 
displaymetrics outmetrics = new displaymetrics(); 
wm.getdefaultdisplay().getmetrics(outmetrics); 
return outmetrics.heightpixels; 
} 
/** 
* 获得状态栏的高度 
* 
* @param context 
* @return 
*/ 
public static int getstatusheight(context context) 
{ 
int statusheight = -; 
try 
{ 
class<?> clazz = class.forname("com.android.internal.r$dimen"); 
object object = clazz.newinstance(); 
int height = integer.parseint(clazz.getfield("status_bar_height") 
.get(object).tostring()); 
statusheight = context.getresources().getdimensionpixelsize(height); 
} catch (exception e) 
{ 
e.printstacktrace(); 
} 
return statusheight; 
} 
/** 
* 获取当前屏幕截图，包含状态栏 
* 
* @param activity 
* @return 
*/ 
public static bitmap snapshotwithstatusbar(activity activity) 
{ 
view view = activity.getwindow().getdecorview(); 
view.setdrawingcacheenabled(true); 
view.builddrawingcache(); 
bitmap bmp = view.getdrawingcache(); 
int width = getscreenwidth(activity); 
int height = getscreenheight(activity); 
bitmap bp = null; 
bp = bitmap.createbitmap(bmp, , , width, height); 
view.destroydrawingcache(); 
return bp; 
} 
/** 
* 获取当前屏幕截图，不包含状态栏 
* 
* @param activity 
* @return 
*/ 
public static bitmap snapshotwithoutstatusbar(activity activity) 
{ 
view view = activity.getwindow().getdecorview(); 
view.setdrawingcacheenabled(true); 
view.builddrawingcache(); 
bitmap bmp = view.getdrawingcache(); 
rect frame = new rect(); 
activity.getwindow().getdecorview().getwindowvisibledisplayframe(frame); 
int statusbarheight = frame.top; 
int width = getscreenwidth(activity); 
int height = getscreenheight(activity); 
bitmap bp = null; 
bp = bitmap.createbitmap(bmp, , statusbarheight, width, height 
- statusbarheight); 
view.destroydrawingcache(); 
return bp; 
} 
}

七、app相关辅助类 apputils.java

public class apputils 
{ 
private apputils() 
{ 
/* cannot be instantiated */ 
throw new unsupportedoperationexception("cannot be instantiated"); 
} 
/** 
* 获取应用程序名称 
*/ 
public static string getappname(context context) 
{ 
try 
{ 
packagemanager packagemanager = context.getpackagemanager(); 
packageinfo packageinfo = packagemanager.getpackageinfo( 
context.getpackagename(), ); 
int labelres = packageinfo.applicationinfo.labelres; 
return context.getresources().getstring(labelres); 
} catch (namenotfoundexception e) 
{ 
e.printstacktrace(); 
} 
return null; 
} 
/** 
* [获取应用程序版本名称信息] 
* 
* @param context 
* @return 当前应用的版本名称 
*/ 
public static string getversionname(context context) 
{ 
try 
{ 
packagemanager packagemanager = context.getpackagemanager(); 
packageinfo packageinfo = packagemanager.getpackageinfo( 
context.getpackagename(), ); 
return packageinfo.versionname; 
} catch (namenotfoundexception e) 
{ 
e.printstacktrace(); 
} 
return null; 
} 
}

八、软键盘相关辅助类keyboardutils.java

/** 
* 打开或关闭软键盘 
*/ 
public class keyboardutils 
{ 
/** 
* 打卡软键盘 
* 
* @param medittext 输入框 
* @param mcontext 上下文 
*/ 
public static void openkeybord(edittext medittext, context mcontext) 
{ 
inputmethodmanager imm = (inputmethodmanager) mcontext 
.getsystemservice(context.input_method_service); 
imm.showsoftinput(medittext, inputmethodmanager.result_shown); 
imm.togglesoftinput(inputmethodmanager.show_forced, 
inputmethodmanager.hide_implicit_only); 
} 
/** 
* 关闭软键盘 
* 
* @param medittext 输入框 
* @param mcontext 上下文 
*/ 
public static void closekeybord(edittext medittext, context mcontext) 
{ 
inputmethodmanager imm = (inputmethodmanager) mcontext 
.getsystemservice(context.input_method_service); 
imm.hidesoftinputfromwindow(medittext.getwindowtoken(), ); 
} 
}

九、网络相关辅助类 netutils.java

public class netutils 
{ 
private netutils() 
{ 
/* cannot be instantiated */ 
throw new unsupportedoperationexception("cannot be instantiated"); 
} 
/** 
* 判断网络是否连接 
*/ 
public static boolean isconnected(context context) 
{ 
connectivitymanager connectivity = (connectivitymanager) context 
.getsystemservice(context.connectivity_service); 
if (null != connectivity) 
{ 
networkinfo info = connectivity.getactivenetworkinfo(); 
if (null != info && info.isconnected()) 
{ 
if (info.getstate() == networkinfo.state.connected) 
{ 
return true; 
} 
} 
} 
return false; 
} 
/** 
* 判断是否是wifi连接 
*/ 
public static boolean iswifi(context context) 
{ 
connectivitymanager cm = (connectivitymanager) context 
.getsystemservice(context.connectivity_service); 
if (cm == null) 
return false; 
return cm.getactivenetworkinfo().gettype() == connectivitymanager.type_wifi; 
} 
/** 
* 打开网络设置界面 
*/ 
public static void opensetting(activity activity) 
{ 
intent intent = new intent("/"); 
componentname cm = new componentname("com.android.settings", 
"com.android.settings.wirelesssettings"); 
intent.setcomponent(cm); 
intent.setaction("android.intent.action.view"); 
activity.startactivityforresult(intent, ); 
} 
}

十、http相关辅助类 httputils.java

/** 
* http请求的工具类 
*/
public class httputils 
{ 
private static final int timeout_in_millions = ; 
public interface callback 
{ 
void onrequestcomplete(string result); 
} 
/** 
* 异步的get请求 
* 
* @param urlstr 
* @param callback 
*/ 
public static void dogetasyn(final string urlstr, final callback callback) 
{ 
new thread() 
{ 
public void run() 
{ 
try 
{ 
string result = doget(urlstr); 
if (callback != null) 
{ 
callback.onrequestcomplete(result); 
} 
} catch (exception e) 
{ 
e.printstacktrace(); 
} 
}; 
}.start(); 
} 
/** 
* 异步的post请求 
* @param urlstr 
* @param params 
* @param callback 
* @throws exception 
*/ 
public static void dopostasyn(final string urlstr, final string params, 
final callback callback) throws exception 
{ 
new thread() 
{ 
public void run() 
{ 
try 
{ 
string result = dopost(urlstr, params); 
if (callback != null) 
{ 
callback.onrequestcomplete(result); 
} 
} catch (exception e) 
{ 
e.printstacktrace(); 
} 
}; 
}.start(); 
} 
/** 
* get请求，获得返回数据 
* 
* @param urlstr 
* @return 
* @throws exception 
*/ 
public static string doget(string urlstr) 
{ 
url url = null; 
httpurlconnection conn = null; 
inputstream is = null; 
bytearrayoutputstream baos = null; 
try 
{ 
url = new url(urlstr); 
conn = (httpurlconnection) url.openconnection(); 
conn.setreadtimeout(timeout_in_millions); 
conn.setconnecttimeout(timeout_in_millions); 
conn.setrequestmethod("get"); 
conn.setrequestproperty("accept", "*/*"); 
conn.setrequestproperty("connection", "keep-alive"); 
if (conn.getresponsecode() == ) 
{ 
is = conn.getinputstream(); 
baos = new bytearrayoutputstream(); 
int len = -; 
byte[] buf = new byte[]; 
while ((len = is.read(buf)) != -) 
{ 
baos.write(buf, , len); 
} 
baos.flush(); 
return baos.tostring(); 
} else 
{ 
throw new runtimeexception(" responsecode is not ... "); 
} 
} catch (exception e) 
{ 
e.printstacktrace(); 
} finally 
{ 
try 
{ 
if (is != null) 
is.close(); 
} catch (ioexception e) 
{ 
} 
try 
{ 
if (baos != null) 
baos.close(); 
} catch (ioexception e) 
{ 
} 
conn.disconnect(); 
} 
return null ; 
} 
/** 
* 向指定 url 发送post方法的请求 
* 
* @param url 
* 发送请求的 url 
* @param param 
* 请求参数，请求参数应该是 name=value&name=value 的形式。 
* @return 所代表远程资源的响应结果 
* @throws exception 
*/ 
public static string dopost(string url, string param) 
{ 
printwriter out = null; 
bufferedreader in = null; 
string result = ""; 
try 
{ 
url realurl = new url(url); 
// 打开和url之间的连接 
httpurlconnection conn = (httpurlconnection) realurl 
.openconnection(); 
// 设置通用的请求属性 
conn.setrequestproperty("accept", "*/*"); 
conn.setrequestproperty("connection", "keep-alive"); 
conn.setrequestmethod("post"); 
conn.setrequestproperty("content-type", 
"application/x-www-form-urlencoded"); 
conn.setrequestproperty("charset", "utf-"); 
conn.setusecaches(false); 
// 发送post请求必须设置如下两行 
conn.setdooutput(true); 
conn.setdoinput(true); 
conn.setreadtimeout(timeout_in_millions); 
conn.setconnecttimeout(timeout_in_millions); 
if (param != null && !param.trim().equals("")) 
{ 
// 获取urlconnection对象对应的输出流 
out = new printwriter(conn.getoutputstream()); 
// 发送请求参数 
out.print(param); 
// flush输出流的缓冲 
out.flush(); 
} 
// 定义bufferedreader输入流来读取url的响应 
in = new bufferedreader( 
new inputstreamreader(conn.getinputstream())); 
string line; 
while ((line = in.readline()) != null) 
{ 
result += line; 
} 
} catch (exception e) 
{ 
e.printstacktrace(); 
} 
// 使用finally块来关闭输出流、输入流 
finally 
{ 
try 
{ 
if (out != null) 
{ 
out.close(); 
} 
if (in != null) 
{ 
in.close(); 
} 
} catch (ioexception ex) 
{ 
ex.printstacktrace(); 
} 
} 
return result; 
} 
}

十一、时间工具类 timeutils.java

public class timeutils {
public static final simpledateformat default_date_format = 
new simpledateformat("yyyy-mm-dd hh:mm:ss");
public static final simpledateformat date_format_date = 
new simpledateformat("yyyy-mm-dd");
private timeutils() {
throw new assertionerror();
}
/**
* long time to string
* 
* @param timeinmillis
* @param dateformat
* @return
*/
public static string gettime(long timeinmillis, simpledateformat dateformat) {
return dateformat.format(new date(timeinmillis));
}
/**
* long time to string, format is {@link #default_date_format}
* 
* @param timeinmillis
* @return
*/
public static string gettime(long timeinmillis) {
return gettime(timeinmillis, default_date_format);
}
/**
* get current time in milliseconds
* 
* @return
*/
public static long getcurrenttimeinlong() {
return system.currenttimemillis();
}
/**
* get current time in milliseconds, format is {@link #default_date_format}
* 
* @return
*/
public static string getcurrenttimeinstring() {
return gettime(getcurrenttimeinlong());
}
/**
* get current time in milliseconds
* 
* @return
*/
public static string getcurrenttimeinstring(simpledateformat dateformat) {
return gettime(getcurrenttimeinlong(), dateformat);
}
}

十二、文件工具类 fileutils.java

public class fileutils {
public final static string file_extension_separator = ".";
private fileutils() {
throw new assertionerror();
}
/**
* read file
* 
* @param filepath
* @param charsetname the name of a supported {@link java.nio.charset.charset </code>charset<code>}
* @return if file not exist, return null, else return content of file
* @throws runtimeexception if an error occurs while operator bufferedreader
*/
public static stringbuilder readfile(string filepath, string charsetname) {
file file = new file(filepath);
stringbuilder filecontent = new stringbuilder("");
if (file == null || !file.isfile()) {
return null;
}
bufferedreader reader = null;
try {
inputstreamreader is = new inputstreamreader(new fileinputstream(file), charsetname);
reader = new bufferedreader(is);
string line = null;
while ((line = reader.readline()) != null) {
if (!filecontent.tostring().equals("")) {
filecontent.append("\r\n");
}
filecontent.append(line);
}
return filecontent;
} catch (ioexception e) {
throw new runtimeexception("ioexception occurred. ", e);
} finally {
ioutils.close(reader);
}
}
/**
* write file
* 
* @param filepath
* @param content
* @param append is append, if true, write to the end of file, else clear content of file and write into it
* @return return false if content is empty, true otherwise
* @throws runtimeexception if an error occurs while operator filewriter
*/
public static boolean writefile(string filepath, string content, boolean append) {
if (stringutils.isempty(content)) {
return false;
}
filewriter filewriter = null;
try {
makedirs(filepath);
filewriter = new filewriter(filepath, append);
filewriter.write(content);
return true;
} catch (ioexception e) {
throw new runtimeexception("ioexception occurred. ", e);
} finally {
ioutils.close(filewriter);
}
}
/**
* write file
* 
* @param filepath
* @param contentlist
* @param append is append, if true, write to the end of file, else clear content of file and write into it
* @return return false if contentlist is empty, true otherwise
* @throws runtimeexception if an error occurs while operator filewriter
*/
public static boolean writefile(string filepath, list<string> contentlist, boolean append) {
if (listutils.isempty(contentlist)) {
return false;
}
filewriter filewriter = null;
try {
makedirs(filepath);
filewriter = new filewriter(filepath, append);
int i = ;
for (string line : contentlist) {
if (i++ > ) {
filewriter.write("\r\n");
}
filewriter.write(line);
}
return true;
} catch (ioexception e) {
throw new runtimeexception("ioexception occurred. ", e);
} finally {
ioutils.close(filewriter);
}
}
/**
* write file, the string will be written to the begin of the file
* 
* @param filepath
* @param content
* @return
*/
public static boolean writefile(string filepath, string content) {
return writefile(filepath, content, false);
}
/**
* write file, the string list will be written to the begin of the file
* 
* @param filepath
* @param contentlist
* @return
*/
public static boolean writefile(string filepath, list<string> contentlist) {
return writefile(filepath, contentlist, false);
}
/**
* write file, the bytes will be written to the begin of the file
* 
* @param filepath
* @param stream
* @return
* @see {@link #writefile(string, inputstream, boolean)}
*/
public static boolean writefile(string filepath, inputstream stream) {
return writefile(filepath, stream, false);
}
/**
* write file
* 
* @param file the file to be opened for writing.
* @param stream the input stream
* @param append if <code>true</code>, then bytes will be written to the end of the file rather than the beginning
* @return return true
* @throws runtimeexception if an error occurs while operator fileoutputstream
*/
public static boolean writefile(string filepath, inputstream stream, boolean append) {
return writefile(filepath != null ? new file(filepath) : null, stream, append);
}
/**
* write file, the bytes will be written to the begin of the file
* 
* @param file
* @param stream
* @return
* @see {@link #writefile(file, inputstream, boolean)}
*/
public static boolean writefile(file file, inputstream stream) {
return writefile(file, stream, false);
}
/**
* write file
* 
* @param file the file to be opened for writing.
* @param stream the input stream
* @param append if <code>true</code>, then bytes will be written to the end of the file rather than the beginning
* @return return true
* @throws runtimeexception if an error occurs while operator fileoutputstream
*/
public static boolean writefile(file file, inputstream stream, boolean append) {
outputstream o = null;
try {
makedirs(file.getabsolutepath());
o = new fileoutputstream(file, append);
byte data[] = new byte[];
int length = -;
while ((length = stream.read(data)) != -) {
o.write(data, , length);
}
o.flush();
return true;
} catch (filenotfoundexception e) {
throw new runtimeexception("filenotfoundexception occurred. ", e);
} catch (ioexception e) {
throw new runtimeexception("ioexception occurred. ", e);
} finally {
ioutils.close(o);
ioutils.close(stream);
}
}
/**
* move file
* 
* @param sourcefilepath
* @param destfilepath
*/
public static void movefile(string sourcefilepath, string destfilepath) {
if (textutils.isempty(sourcefilepath) || textutils.isempty(destfilepath)) {
throw new runtimeexception("both sourcefilepath and destfilepath cannot be null.");
}
movefile(new file(sourcefilepath), new file(destfilepath));
}
/**
* move file
* 
* @param srcfile
* @param destfile
*/
public static void movefile(file srcfile, file destfile) {
boolean rename = srcfile.renameto(destfile);
if (!rename) {
copyfile(srcfile.getabsolutepath(), destfile.getabsolutepath());
deletefile(srcfile.getabsolutepath());
}
}
/**
* copy file
* 
* @param sourcefilepath
* @param destfilepath
* @return
* @throws runtimeexception if an error occurs while operator fileoutputstream
*/
public static boolean copyfile(string sourcefilepath, string destfilepath) {
inputstream inputstream = null;
try {
inputstream = new fileinputstream(sourcefilepath);
} catch (filenotfoundexception e) {
throw new runtimeexception("filenotfoundexception occurred. ", e);
}
return writefile(destfilepath, inputstream);
}
/**
* read file to string list, a element of list is a line
* 
* @param filepath
* @param charsetname the name of a supported {@link java.nio.charset.charset </code>charset<code>}
* @return if file not exist, return null, else return content of file
* @throws runtimeexception if an error occurs while operator bufferedreader
*/
public static list<string> readfiletolist(string filepath, string charsetname) {
file file = new file(filepath);
list<string> filecontent = new arraylist<string>();
if (file == null || !file.isfile()) {
return null;
}
bufferedreader reader = null;
try {
inputstreamreader is = new inputstreamreader(new fileinputstream(file), charsetname);
reader = new bufferedreader(is);
string line = null;
while ((line = reader.readline()) != null) {
filecontent.add(line);
}
return filecontent;
} catch (ioexception e) {
throw new runtimeexception("ioexception occurred. ", e);
} finally {
ioutils.close(reader);
}
}
/**
* get file name from path, not include suffix
* 
* <pre>
* getfilenamewithoutextension(null) = null
* getfilenamewithoutextension("") = ""
* getfilenamewithoutextension(" ") = " "
* getfilenamewithoutextension("abc") = "abc"
* getfilenamewithoutextension("a.mp") = "a"
* getfilenamewithoutextension("a.b.rmvb") = "a.b"
* getfilenamewithoutextension("c:\\") = ""
* getfilenamewithoutextension("c:\\a") = "a"
* getfilenamewithoutextension("c:\\a.b") = "a"
* getfilenamewithoutextension("c:a.txt\\a") = "a"
* getfilenamewithoutextension("/home/admin") = "admin"
* getfilenamewithoutextension("/home/admin/a.txt/b.mp") = "b"
* </pre>
* 
* @param filepath
* @return file name from path, not include suffix
* @see
*/
public static string getfilenamewithoutextension(string filepath) {
if (stringutils.isempty(filepath)) {
return filepath;
}
int extenposi = filepath.lastindexof(file_extension_separator);
int fileposi = filepath.lastindexof(file.separator);
if (fileposi == -) {
return (extenposi == - ? filepath : filepath.substring(, extenposi));
}
if (extenposi == -) {
return filepath.substring(fileposi + );
}
return (fileposi < extenposi ? filepath.substring(fileposi + , extenposi) : filepath.substring(fileposi + ));
}
/**
* get file name from path, include suffix
* 
* <pre>
* getfilename(null) = null
* getfilename("") = ""
* getfilename(" ") = " "
* getfilename("a.mp") = "a.mp"
* getfilename("a.b.rmvb") = "a.b.rmvb"
* getfilename("abc") = "abc"
* getfilename("c:\\") = ""
* getfilename("c:\\a") = "a"
* getfilename("c:\\a.b") = "a.b"
* getfilename("c:a.txt\\a") = "a"
* getfilename("/home/admin") = "admin"
* getfilename("/home/admin/a.txt/b.mp") = "b.mp"
* </pre>
* 
* @param filepath
* @return file name from path, include suffix
*/
public static string getfilename(string filepath) {
if (stringutils.isempty(filepath)) {
return filepath;
}
int fileposi = filepath.lastindexof(file.separator);
return (fileposi == -) ? filepath : filepath.substring(fileposi + );
}
/**
* get folder name from path
* 
* <pre>
* getfoldername(null) = null
* getfoldername("") = ""
* getfoldername(" ") = ""
* getfoldername("a.mp") = ""
* getfoldername("a.b.rmvb") = ""
* getfoldername("abc") = ""
* getfoldername("c:\\") = "c:"
* getfoldername("c:\\a") = "c:"
* getfoldername("c:\\a.b") = "c:"
* getfoldername("c:a.txt\\a") = "c:a.txt"
* getfoldername("c:a\\b\\c\\d.txt") = "c:a\\b\\c"
* getfoldername("/home/admin") = "/home"
* getfoldername("/home/admin/a.txt/b.mp") = "/home/admin/a.txt"
* </pre>
* 
* @param filepath
* @return
*/
public static string getfoldername(string filepath) {
if (stringutils.isempty(filepath)) {
return filepath;
}
int fileposi = filepath.lastindexof(file.separator);
return (fileposi == -) ? "" : filepath.substring(, fileposi);
}
/**
* get suffix of file from path
* 
* <pre>
* getfileextension(null) = ""
* getfileextension("") = ""
* getfileextension(" ") = " "
* getfileextension("a.mp") = "mp"
* getfileextension("a.b.rmvb") = "rmvb"
* getfileextension("abc") = ""
* getfileextension("c:\\") = ""
* getfileextension("c:\\a") = ""
* getfileextension("c:\\a.b") = "b"
* getfileextension("c:a.txt\\a") = ""
* getfileextension("/home/admin") = ""
* getfileextension("/home/admin/a.txt/b") = ""
* getfileextension("/home/admin/a.txt/b.mp") = "mp"
* </pre>
* 
* @param filepath
* @return
*/
public static string getfileextension(string filepath) {
if (stringutils.isblank(filepath)) {
return filepath;
}
int extenposi = filepath.lastindexof(file_extension_separator);
int fileposi = filepath.lastindexof(file.separator);
if (extenposi == -) {
return "";
}
return (fileposi >= extenposi) ? "" : filepath.substring(extenposi + );
}
/**
* creates the directory named by the trailing filename of this file, including the complete directory path required
* to create this directory. <br/>
* <br/>
* <ul>
* <strong>attentions:</strong>
* <li>makedirs("c:\\users\\trinea") can only create users folder</li>
* <li>makefolder("c:\\users\\trinea\\") can create trinea folder</li>
* </ul>
* 
* @param filepath
* @return true if the necessary directories have been created or the target directory already exists, false one of
* the directories can not be created.
* <ul>
* <li>if {@link fileutils#getfoldername(string)} return null, return false</li>
* <li>if target directory already exists, return true</li>
* <li>return {@link java.io.file#makefolder}</li>
* </ul>
*/
public static boolean makedirs(string filepath) {
string foldername = getfoldername(filepath);
if (stringutils.isempty(foldername)) {
return false;
}
file folder = new file(foldername);
return (folder.exists() && folder.isdirectory()) ? true : folder.mkdirs();
}
/**
* @param filepath
* @return
* @see #makedirs(string)
*/
public static boolean makefolders(string filepath) {
return makedirs(filepath);
}
/**
* indicates if this file represents a file on the underlying file system.
* 
* @param filepath
* @return
*/
public static boolean isfileexist(string filepath) {
if (stringutils.isblank(filepath)) {
return false;
}
file file = new file(filepath);
return (file.exists() && file.isfile());
}
/**
* indicates if this file represents a directory on the underlying file system.
* 
* @param directorypath
* @return
*/
public static boolean isfolderexist(string directorypath) {
if (stringutils.isblank(directorypath)) {
return false;
}
file dire = new file(directorypath);
return (dire.exists() && dire.isdirectory());
}
/**
* delete file or directory
* <ul>
* <li>if path is null or empty, return true</li>
* <li>if path not exist, return true</li>
* <li>if path exist, delete recursion. return true</li>
* <ul>
* 
* @param path
* @return
*/
public static boolean deletefile(string path) {
if (stringutils.isblank(path)) {
return true;
}
file file = new file(path);
if (!file.exists()) {
return true;
}
if (file.isfile()) {
return file.delete();
}
if (!file.isdirectory()) {
return false;
}
for (file f : file.listfiles()) {
if (f.isfile()) {
f.delete();
} else if (f.isdirectory()) {
deletefile(f.getabsolutepath());
}
}
return file.delete();
}
/**
* get file size
* <ul>
* <li>if path is null or empty, return -</li>
* <li>if path exist and it is a file, return file size, else return -</li>
* <ul>
* 
* @param path
* @return returns the length of this file in bytes. returns - if the file does not exist.
*/
public static long getfilesize(string path) {
if (stringutils.isblank(path)) {
return -;
}
file file = new file(path);
return (file.exists() && file.isfile() ? file.length() : -);
}
}

十三、assets和raw资源工具类 resourceutils.java

public class resourceutils {
private resourceutils() {
throw new assertionerror();
}
/**
* get an asset using access_streaming mode. this provides access to files that have been bundled with an
* application as assets -- that is, files placed in to the "assets" directory.
* 
* @param context
* @param filename the name of the asset to open. this name can be hierarchical.
* @return
*/
public static string gefilefromassets(context context, string filename) {
if (context == null || stringutils.isempty(filename)) {
return null;
}
stringbuilder s = new stringbuilder("");
try {
inputstreamreader in = new inputstreamreader(context.getresources().getassets().open(filename));
bufferedreader br = new bufferedreader(in);
string line;
while ((line = br.readline()) != null) {
s.append(line);
}
return s.tostring();
} catch (ioexception e) {
e.printstacktrace();
return null;
}
}
/**
* get content from a raw resource. this can only be used with resources whose value is the name of an asset files
* -- that is, it can be used to open drawable, sound, and raw resources; it will fail on string and color
* resources.
* 
* @param context
* @param resid the resource identifier to open, as generated by the appt tool.
* @return
*/
public static string gefilefromraw(context context, int resid) {
if (context == null) {
return null;
}
stringbuilder s = new stringbuilder();
try {
inputstreamreader in = new inputstreamreader(context.getresources().openrawresource(resid));
bufferedreader br = new bufferedreader(in);
string line;
while ((line = br.readline()) != null) {
s.append(line);
}
return s.tostring();
} catch (ioexception e) {
e.printstacktrace();
return null;
}
}
/**
* same to {@link resourceutils#gefilefromassets(context, string)}, but return type is list<string>
* 
* @param context
* @param filename
* @return
*/
public static list<string> gefiletolistfromassets(context context, string filename) {
if (context == null || stringutils.isempty(filename)) {
return null;
}
list<string> filecontent = new arraylist<string>();
try {
inputstreamreader in = new inputstreamreader(context.getresources().getassets().open(filename));
bufferedreader br = new bufferedreader(in);
string line;
while ((line = br.readline()) != null) {
filecontent.add(line);
}
br.close();
return filecontent;
} catch (ioexception e) {
e.printstacktrace();
return null;
}
}
/**
* same to {@link resourceutils#gefilefromraw(context, int)}, but return type is list<string>
* 
* @param context
* @param resid
* @return
*/
public static list<string> gefiletolistfromraw(context context, int resid) {
if (context == null) {
return null;
}
list<string> filecontent = new arraylist<string>();
bufferedreader reader = null;
try {
inputstreamreader in = new inputstreamreader(context.getresources().openrawresource(resid));
reader = new bufferedreader(in);
string line = null;
while ((line = reader.readline()) != null) {
filecontent.add(line);
}
reader.close();
return filecontent;
} catch (ioexception e) {
e.printstacktrace();
return null;
}
}
}

十四、单例工具类 singletonutils.java

public abstract class singletonutils<t> {
private t instance;
protected abstract t newinstance();
public final t getinstance() {
if (instance == null) {
synchronized (singletonutils.class) {
if (instance == null) {
instance = newinstance();
}
}
}
return instance;
}
}

十五、数据库工具类 sqliteutils.java

public class sqliteutils {
private static volatile sqliteutils instance;
private dbhelper dbhelper;
private sqlitedatabase db;
private sqliteutils(context context) {
dbhelper = new dbhelper(context);
db = dbhelper.getwritabledatabase();
}
public static sqliteutils getinstance(context context) {
if (instance == null) {
synchronized (sqliteutils.class) {
if (instance == null) {
instance = new sqliteutils(context);
}
}
}
return instance;
}
public sqlitedatabase getdb() {
return db;
}
}