android客户端从服务器端获取json数据并解析的实现代码
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2023-11-12 09:56:46
首先客户端从服务器端获取json数据
1、利用httpurlconnection
复制代码 代码如下:/** ...
首先客户端从服务器端获取json数据
1、利用httpurlconnection
复制代码 代码如下:
/**
* 从指定的url中获取数组
* @param urlpath
* @return
* @throws exception
*/
public static string readparse(string urlpath) throws exception {
bytearrayoutputstream outstream = new bytearrayoutputstream();
byte[] data = new byte[1024];
int len = 0;
url url = new url(urlpath);
httpurlconnection conn = (httpurlconnection) url.openconnection();
inputstream instream = conn.getinputstream();
while ((len = instream.read(data)) != -1) {
outstream.write(data, 0, len);
}
instream.close();
return new string(outstream.tobytearray());//通过out.stream.tobytearray获取到写的数据
}
2、利用httpclient
复制代码 代码如下:
/**
* 访问数据库并返回json数据字符串
*
* @param params 向服务器端传的参数
* @param url
* @return
* @throws exception
*/
public static string dopost(list<namevaluepair> params, string url)
throws exception {
string result = null;
// 获取httpclient对象
httpclient httpclient = new defaulthttpclient();
// 新建httppost对象
httppost httppost = new httppost(url);
if (params != null) {
// 设置字符集
httpentity entity = new urlencodedformentity(params, http.utf_8);
// 设置参数实体
httppost.setentity(entity);
}
/*// 连接超时
httpclient.getparams().setparameter(
coreconnectionpnames.connection_timeout, 3000);
// 请求超时
httpclient.getparams().setparameter(coreconnectionpnames.so_timeout,
3000);*/
// 获取httpresponse实例
httpresponse httpresp = httpclient.execute(httppost);
// 判断是够请求成功
if (httpresp.getstatusline().getstatuscode() == 200) {
// 获取返回的数据
result = entityutils.tostring(httpresp.getentity(), "utf-8");
} else {
log.i("httppost", "httppost方式请求失败");
}
return result;
}
其次json数据解析：
json数据：[{"id":"67","biaoti":"g","logo":"http://www.nuoter.com/wtserver/resources/upload/13508741845270.png","logolunbo":"http://www.nuoter.com/wtserver/resources/upload/13509015004480.jpg","yuanjia":"0","xianjia":"0"},{"id":"64","biaoti":"444","logo":"http://www.nuoter.com/wtserver/resources/upload/13508741704400.png","logolunbo":"http://172.16.1.75:8080/wtserver/resources/upload/13508741738500.png","yuanjia":"0","xianjia":"0"},{"id":"62","biaoti":"jhadasd","logo":"http://www.nuoter.com/wtserver/resources/upload/13508741500450.png","logolunbo":"http://172.16.1.75:8080/wtserver/resources/upload/13508741557450.png","yuanjia":"1","xianjia":"0"}]
复制代码 代码如下:
/**
* 解析
*
* @throws jsonexception
*/
private static arraylist<hashmap<string, object>> analysis(string jsonstr)
throws jsonexception {
/******************* 解析 ***********************/
jsonarray jsonarray = null;
// 初始化list数组对象
arraylist<hashmap<string, object>> list = new arraylist<hashmap<string, object>>();
jsonarray = new jsonarray(jsonstr);
for (int i = 0; i < jsonarray.length(); i++) {
jsonobject jsonobject = jsonarray.getjsonobject(i);
// 初始化map数组对象
hashmap<string, object> map = new hashmap<string, object>();
map.put("logo", jsonobject.getstring("logo"));
map.put("logolunbo", jsonobject.getstring("logolunbo"));
map.put("biaoti", jsonobject.getstring("biaoti"));
map.put("yuanjia", jsonobject.getstring("yuanjia"));
map.put("xianjia", jsonobject.getstring("xianjia"));
map.put("id", jsonobject.getint("id"));
list.add(map);
}
return list;
}
最后数据适配：
1、textview
复制代码 代码如下:
/**
* readparse（string）从服务器端获取数据
* analysis（string）解析json数据
*/
private void resultjson() {
try {
alldata = analysis(readparse(url));
iterator<hashmap<string, object>> it = alldata.iterator();
while (it.hasnext()) {
map<string, object> ma = it.next();
if ((integer) ma.get("id") == id) {
biaoti.settext((string) ma.get("biaoti"));
yuanjia.settext((string) ma.get("yuanjia"));
xianjia.settext((string) ma.get("xianjia"));
}
}
} catch (jsonexception e) {
e.printstacktrace();
} catch (exception e) {
e.printstacktrace();
}
}
2、listview：
复制代码 代码如下:
/**
* listview 数据适配
*/
private void product_data(){
list<hashmap<string, object>> lists = null;
try {
lists = analysis(readparse(url));//解析出json数据
} catch (exception e) {
// todo auto-generated catch block
e.printstacktrace();
}
list<hashmap<string, object>> data = new arraylist<hashmap<string,object>>();
for(hashmap<string, object> news : lists){
hashmap<string, object> item = new hashmap<string, object>();
item.put("chuxingtianshu", news.get("chuxingtianshu"));
item.put("biaoti", news.get("biaoti"));
item.put("yuanjia", news.get("yuanjia"));
item.put("xianjia", news.get("xianjia"));
item.put("id", news.get("id"));
try {
bitmap = imageservice.getimage(news.get("logo").tostring());//图片从服务器上获取
} catch (exception e) {
// todo auto-generated catch block
e.printstacktrace();
}
if(bitmap==null){
log.i("bitmap", ""+bitmap);
toast.maketext(travelline.this, "图片加载错误", toast.length_short)
.show(); // 显示图片编号
}
item.put("logo",bitmap);
data.add(item);
}
listitemadapter = new mysimpleadapter1(travelline.this,data,r.layout.a_travelline_item,
// 动态数组与imageitem对应的子项
new string[] { "logo", "biaoti",
"xianjia", "yuanjia", "chuxingtianshu"},
// imageitem的xml文件里面的一个imageview,两个textview id
new int[] { r.id.trl_itemimage, r.id.trl_itemtitle,
r.id.trl_itemcontent, r.id.trl_itemmoney,
r.id.trl_itemtoday});
listview.setadapter(listitemadapter);
//添加点击
listview.setonitemclicklistener(new onitemclicklistener() {
public void onitemclick(adapterview<?> arg0, view arg1, int arg2,
long arg3) {
login_publicchannel_trl_sub(arg2);
}
});
}
对于有图片的要重写适配器
复制代码 代码如下:
package com.nuoter.adapteruntil;
import java.util.hashmap;
import java.util.list;
import android.content.context;
import android.graphics.bitmap;
import android.graphics.bitmapfactory;
import android.graphics.paint;
import android.net.uri;
import android.view.layoutinflater;
import android.view.view;
import android.view.viewgroup;
import android.widget.baseadapter;
import android.widget.imageview;
import android.widget.linearlayout;
import android.widget.textview;
public class mysimpleadapter1 extends baseadapter {
private layoutinflater minflater;
private list<hashmap<string, object>> list;
private int layoutid;
private string flag[];
private int itemids[];
public mysimpleadapter1(context context, list<hashmap<string, object>> list,
int layoutid, string flag[], int itemids[]) {
this.minflater = layoutinflater.from(context);
this.list = list;
this.layoutid = layoutid;
this.flag = flag;
this.itemids = itemids;
}
@override
public int getcount() {
// todo auto-generated method stub
return list.size();
}
@override
public object getitem(int arg0) {
// todo auto-generated method stub
return 0;
}
@override
public long getitemid(int arg0) {
// todo auto-generated method stub
return 0;
}
@override
public view getview(int position, view convertview, viewgroup parent) {
convertview = minflater.inflate(layoutid, null);
// convertview = minflater.inflate(layoutid, null);
for (int i = 0; i < flag.length; i++) {//备注1
if (convertview.findviewbyid(itemids[i]) instanceof imageview) {
imageview imgview = (imageview) convertview.findviewbyid(itemids[i]);
imgview.setimagebitmap((bitmap) list.get(position).get(flag[i]));///////////关键是这句!!!!!!!!!!!!!!!
}else if (convertview.findviewbyid(itemids[i]) instanceof textview) {
textview tv = (textview) convertview.findviewbyid(itemids[i]);
tv.settext((string) list.get(position).get(flag[i]));
}else{
//...备注2
}
}
//addlistener(convertview);
return convertview;
}
/* public void addlistener(final view convertview) {
imageview imgview = (imageview)convertview.findviewbyid(r.id.lxs_item_image);
} */
}
对于图片的获取，json解析出来的是字符串url："logolunbo":http://www.nuoter.com/wtserver/resources/upload/13509015004480.jpg 从url获取 图片
imageservice工具类
复制代码 代码如下:
package com.nuoter.adapteruntil;
import java.io.bytearrayoutputstream;
import java.io.inputstream;
import java.net.httpurlconnection;
import java.net.url;
import android.graphics.bitmap;
import android.graphics.bitmapfactory;
public class imageservice {
/**
* 获取网络图片的数据
* @param path 网络图片路径
* @return
*/
public static bitmap getimage(string path) throws exception{
/*url url = new url(imageurl);
httpurlconnection conn = (httpurlconnection) url.openconnection();
inputstream is = conn.getinputstream();
mbitmap = bitmapfactory.decodestream(is);*/
bitmap bitmap= null;
url url = new url(path);
httpurlconnection conn = (httpurlconnection) url.openconnection();//基于http协议连接对象
conn.setconnecttimeout(5000);
conn.setrequestmethod("get");
if(conn.getresponsecode() == 200){
inputstream instream = conn.getinputstream();
bitmap = bitmapfactory.decodestream(instream);
}
return bitmap;
}
/**
* 读取流中的数据 从url获取json数据
* @param instream
* @return
* @throws exception
*/
public static byte[] read(inputstream instream) throws exception{
bytearrayoutputstream outstream = new bytearrayoutputstream();
byte[] buffer = new byte[1024];
int len = 0;
while( (len = instream.read(buffer)) != -1){
outstream.write(buffer, 0, len);
}
instream.close();
return outstream.tobytearray();
}
}
上面也将从url处获取网络数据写在了工具类imageservice中方面调用，因为都是一样的。
当然也可以在activity类中写一个获取服务器图片的函数（当用处不多时）
复制代码 代码如下:
/*
* 从服务器取图片
* 参数：string类型
* 返回：bitmap类型
*/
public static bitmap gethttpbitmap(string urlpath) {
bitmap bitmap = null;
try {
//生成一个url对象
url url = new url(urlpath);
//打开连接
httpurlconnection conn = (httpurlconnection)url.openconnection();
// conn.setconnecttimeout(6*1000);
// conn.setdoinput(true);
conn.connect();
//得到数据流
inputstream inputstream = conn.getinputstream();
bitmap = bitmapfactory.decodestream(inputstream);
//关闭输入流
inputstream.close();
//关闭连接
conn.disconnect();
} catch (exception e) {
log.i("mytag", "error:"+e.tostring());
}
return bitmap;
}
调用：
复制代码 代码如下:
public imageview pic;
.....
.....
alldata=analysis(readparse(url));
iterator<hashmap<string, object>> it=alldata.iterator();
while(it.hasnext()){
map<string, object> ma=it.next();
if((integer)ma.get("id")==id)
{
logo=(string) ma.get("logo");
bigpic=gethttpbitmap(logo);
}
}
pic.setimagebitmap(bigpic);
另附 下载数据很慢时建立子线程并传参：
复制代码 代码如下:
new thread() {
@override
public void run() {
// 参数列表
list<namevaluepair> namevaluepairs = new arraylist<namevaluepair>();
namevaluepairs.add(new basicnamevaluepair("currpage", integer
.tostring(1)));
namevaluepairs.add(new basicnamevaluepair("pagesize", integer
.tostring(5)));
try {
string result = dopost(namevaluepairs, post_url);
message msg = handler.obtainmessage(1, 1, 1, result);
handler.sendmessage(msg); // 发送消息
} catch (exception e) {
// todo auto-generated catch block
e.printstacktrace();
}
}
}.start();
// 定义handler对象
handler = new handler() {
public void handlemessage(message msg) {
switch (msg.what) {
case 1:{
// 处理ui
stringbuffer strbuf = new stringbuffer();
list<hashmap<string, object>> lists = null;
try {
lists = mainactivity.this
.parsejson(msg.obj.tostring());
} catch (exception e) {
// todo auto-generated catch block
e.printstacktrace();
}
list<hashmap<string, object>> data = new arraylist<hashmap<string,object>>();
for(hashmap<string, object> news : lists){
hashmap<string, object> item = new hashmap<string, object>();
item.put("id", news.get("id"));
item.put("itemtext0", news.get("name"));
try {
bitmap = imageservice.getimage(news.get("logo").tostring());
} catch (exception e) {
// todo auto-generated catch block
e.printstacktrace();
}
if(bitmap==null){
log.i("bitmap", ""+bitmap);
toast.maketext(mainactivity.this, "图片加载错误", toast.length_short)
.show(); // 显示图片编号
}
item.put("itemimage",bitmap);
data.add(item);
}
//生成适配器的imageitem <====> 动态数组的元素，两者一一对应
mysimpleadapter saimageitems = new mysimpleadapter(mainactivity.this, data,
r.layout.d_travelagence_item,
new string[] {"itemimage", "itemtext0", "itemtext1"},
new int[] {r.id.lxs_item_image, r.id.lxs_item_text0, r.id.lxs_item_text1});
//添加并且显示
gridview.setadapter(saimageitems);
}
break;
default:
break;
}
}
};
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