Android实现文件存储案例

本文实例为大家分享了android实现文件存储的具体代码，供大家参考，具体内容如下

1、文件存储案例

public class testactivity extends appcompatactivity {
    private edittext mfileedit;

    @override
    protected void oncreate(bundle savedinstancestate) {
        super.oncreate(savedinstancestate);
        setcontentview(r.layout.activity_test);
        initview();
    }

    private void initview() {
        mfileedit = findviewbyid(r.id.fileedit);
        string inputtext = load();
        if (!textutils.isempty(inputtext)) {
            mfileedit.settext(inputtext);
            mfileedit.setselection(inputtext.length());
            toast.maketext(this, "restoring succeeded", toast.length_short).show();
        }
    }


    @override
    protected void ondestroy() {
        super.ondestroy();
        string inputtext = mfileedit.gettext().tostring();
        save(inputtext);
    }

    //    从文件中读取数据
    public void save(string inputtext) {
        fileoutputstream outputstream = null;
        bufferedwriter writer = null;
        try {
            outputstream = openfileoutput("data", context.mode_private);
            writer = new bufferedwriter(new outputstreamwriter(outputstream));
            writer.write(inputtext);
        } catch (ioexception e) {
            e.printstacktrace();
        } finally {
            try {
                if (writer != null) {
                    writer.close();
                }
            } catch (ioexception e) {
                e.printstacktrace();
            }
        }
    }

    //    将文件存储到文件中
    public string load() {
        fileinputstream inputstream = null;
        bufferedreader reader = null;
        stringbuilder builder = new stringbuilder();
        try {
            inputstream = openfileinput("data");
            reader = new bufferedreader(new inputstreamreader(inputstream));
            string line = "";
            while ((line = reader.readline()) != null) {
                builder.append(line);
            }
        } catch (ioexception e) {
            e.printstacktrace();
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (ioexception e) {
                    e.printstacktrace();
                }
            }
        }
        return builder.tostring();
    }
}

运行结果，pass

2、sharepreferences存储案例

public class sharepfsactivity extends appcompatactivity implements view.onclicklistener {
    private static final string tag = "sharepfsactivity";
    private button mshareddata;
    private button mrestoredata;

    @override
    protected void oncreate(bundle savedinstancestate) {
        super.oncreate(savedinstancestate);
        setcontentview(r.layout.activity_shared_pfs);
        initview();
    }

    private void initview() {
        mshareddata = findviewbyid(r.id.sharedbtn);
        mshareddata.setonclicklistener(this);
        mrestoredata = findviewbyid(r.id.restorebtn);
        mrestoredata.setonclicklistener(this);
    }

    @override
    public void onclick(view view) {
        switch (view.getid()) {
            case r.id.sharedbtn:
                shareddata();
                break;
            case r.id.restorebtn:
                restoredata();
                break;
            default:
                break;
        }
    }

    private void shareddata() {
        sharedpreferences.editor editor = getsharedpreferences("sharedata", mode_private).edit();
        editor.putstring("name", "功勋");
        editor.putstring("type", "电影");
        editor.apply();
    }

    private void restoredata() {
        sharedpreferences preferences = getsharedpreferences("sharedata", mode_private);
        string name = preferences.getstring("name", "");
        string type = preferences.getstring("type", "");
        log.d(tag, "名称：" + name + "，类型：" + type);
    }
}

运行结果，pass

3、登录页面，实现记住username和pwd功能

activity_login.xml文件

<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical">

    <linearlayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <textview
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="用户名：" />

        <edittext
            android:id="@+id/username"
            android:layout_width="240dp"
            android:layout_height="wrap_content" />
    </linearlayout>

    <linearlayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <textview
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="密    码：" />

        <edittext
            android:id="@+id/pwd"
            android:layout_width="240dp"
            android:layout_height="wrap_content" />
    </linearlayout>

    <linearlayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <checkbox
            android:id="@+id/remember"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

        <textview
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="remeber password" />
    </linearlayout>

    <button
        android:id="@+id/login"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="登录" />

</linearlayout>

loginactivity .class

public class loginactivity extends appcompatactivity {
    private static final string tag = "loginactivity";
    private button mlogin;
    private checkbox mremember;
    private edittext musername;
    private edittext mpwd;
    private sharedpreferences msharedps;
    private sharedpreferences.editor meditor;

    @override
    protected void oncreate(bundle savedinstancestate) {
        super.oncreate(savedinstancestate);
        setcontentview(r.layout.activity_login);
        initview();
    }

    private void initview() {
        msharedps = preferencemanager.getdefaultsharedpreferences(this);
        musername = findviewbyid(r.id.username);
        mpwd = findviewbyid(r.id.pwd);
        mremember = findviewbyid(r.id.remember);
        mlogin = findviewbyid(r.id.login);
        boolean isremember = msharedps.getboolean("remember_pwd", false);
        if (isremember) {
            // 将账号和密码都设置到文本框中
            musername.settext(msharedps.getstring("username", ""));
            mpwd.settext(msharedps.getstring("pwd", ""));
            mremember.setchecked(true);
        }
        mlogin.setonclicklistener(new view.onclicklistener() {
            @override
            public void onclick(view v) {
                string username = musername.gettext().tostring();
                string pwd = mpwd.gettext().tostring();
                // 如果账号：admin，密码：123456，就认为登录成功
                if (username.equals("admin") && pwd.equals("123456")) {
                    meditor = msharedps.edit();
                    // 检查复选框是否被选中
                    if (mremember.ischecked()) {
                        meditor.putstring("username", username);
                        meditor.putstring("pwd", pwd);
                        meditor.putboolean("remember_pwd", true);
                    } else {
                        meditor.clear();
                    }
                    meditor.apply();
                    intent intent = new intent(loginactivity.this, mainactivity.class);
                    startactivity(intent);
                    finish();
                } else {
                    log.d(tag, "用户名或密码输入错误，请重新输入");
                }
            }
        });
    }
}

运行结果，pass

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。