版本更新

1.导包 ：Xutils   Gson

  加权限 ： 网络、读写权限  "android.permission.MOUNT_UNMOUNT_FILESYSTEMS"

2.定义一个类 继承Application，然后初始化x.Ext.init(this);

   x.Ext.setDebug(BuildConfig.DEBUG);然后在MainActivity中，

   x.view().inject(this);

3.定义一个类，写一个用来获取当前应用的版本号的方法，包管理 PackageManager

包名字getPackageName            包信息 PackageInfo 

应用的版本  codepackageInfo.versionCode

4.然后写Bean类，数据

5.解析数据Gson,得到messageBean对象，判断messageBean成功后，是否有更新。如果有更新，在判断是否是强制更新还是选择更新，如果没更新，吐司就行。

6.如果是强制更新，就弹出一个框AlertDialog，设置标题为版本更新，设置消息为升级到最新版本，设置为不可取消；如果是选择更新，也弹出一个框AlertDialog，设置消息为是否要升级到最新版本。

   这两个要升级的时候，都需要下载的目录，定义一个版本更新的方法，设置下载保存路径 params.setSaveFilePath()，用xutils的文件下载，实现ProgressCallback接口，重写7个方法，在onLoading中，进行设置进度条。成功了就隐藏进度条，并且安装apk。

代码：

BaseApplication：

import android.app.Application;import org.xutils.x;public class BaseApplication extends Application {    @Override    public void onCreate() {        super.onCreate();        x.Ext.init(this);        x.Ext.setDebug(BuildConfig.DEBUG);    }}
VersionUtils：
package com.bawei.liujie.versonupdate;import android.content.Context;import android.content.pm.PackageInfo;import android.content.pm.PackageManager;public class VersionUtils {    /**     * 获取当前应用的versionCode     */    public static int getVersionCode(Context context) {        int versionCode = 0;        try {            // 包管理            PackageManager packageManager = context.getPackageManager();            // 包名字            String packageName = context.getPackageName();            // 包信息            PackageInfo packageInfo = packageManager.getPackageInfo(packageName, 0);            // 应用的版本code            versionCode = packageInfo.versionCode;        } catch (PackageManager.NameNotFoundException e) {            e.printStackTrace();        }        return versionCode;    }}
Message：
public class Message<T> {    private boolean success;    private String message;    private T result;    public boolean isSuccess() {        return success;    }    public void setSuccess(boolean success) {        this.success = success;    }    public String getMessage() {        return message;    }    public void setMessage(String message) {        this.message = message;    }    public T getResult() {        return result;    }    public void setResult(T result) {        this.result = result;    }}
Version：import com.google.gson.annotations.SerializedName;public class Version {    @SerializedName("has_new_version")    private boolean hasNewVersion;    @SerializedName("must_update")    private boolean mustUpdate;    private String url;    public boolean isHasNewVersion() {        return hasNewVersion;    }    public void setHasNewVersion(boolean hasNewVersion) {        this.hasNewVersion = hasNewVersion;    }    public boolean isMustUpdate() {        return mustUpdate;    }    public void setMustUpdate(boolean mustUpdate) {        this.mustUpdate = mustUpdate;    }    public String getUrl() {        return url;    }    public void setUrl(String url) {        this.url = url;    }}
mainactivity中：import android.app.ProgressDialog;import android.content.DialogInterface;import android.content.Intent;import android.net.Uri;import android.os.Bundle;import android.os.Environment;import android.support.v7.app.AlertDialog;import android.support.v7.app.AppCompatActivity;import android.util.Log;import android.view.View;import android.widget.Toast;import com.google.gson.Gson;import com.google.gson.reflect.TypeToken;import org.xutils.common.Callback;import org.xutils.http.RequestParams;import org.xutils.view.annotation.ContentView;import org.xutils.view.annotation.Event;import org.xutils.x;import java.io.File;import java.lang.reflect.Type;@ContentView(R.layout.activity_main)public class MainActivity extends AppCompatActivity {    private static final String TAG = "MainActivity";    private String url = "http://172.18.47.28/checkversion.php";    // 文件保存地址    private String targetPath = "";    private ProgressDialog progressDialog;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        x.view().inject(this);        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {            File file = Environment.getExternalStorageDirectory();            targetPath = file.getAbsolutePath() + File.separator;        }        progressDialog = new ProgressDialog(this);        progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);    }    @Event(R.id.btn_check_version)    private void btnClick(View v) {        checkVerson();    }    /**     * 检查版本号     */    private void checkVerson() {        int versionCode = VersionUtils.getVersionCode(this);        RequestParams params = new RequestParams(url);        params.addQueryStringParameter("version", String.valueOf(versionCode));        x.http().get(params, new Callback.CommonCallback<String>() {            @Override            public void onSuccess(String result) {                Log.i("---------", "onSuccess: " + result);                Gson gson = new Gson();                Type type = new TypeToken<Message<Version>>() {                }.getType();                Message<Version> messageBean = gson.fromJson(result, type);                if (messageBean.isSuccess()) {                    final Version version = messageBean.getResult();                    // 有更新                    if (version.isHasNewVersion()) {                        // 强制更新                        if (version.isMustUpdate()) {                            new AlertDialog.Builder(MainActivity.this)                                    .setTitle("版本更新")                                    .setMessage("升级到最新版本")                                    .setPositiveButton("确定", new DialogInterface.OnClickListener() {                                        @Override                                        public void onClick(DialogInterface dialog, int which) {                                            updateVersion(version.getUrl());                                            dialog.dismiss();                                        }                                    })                                    // 不可取消                                    .setCancelable(false)                                    .create().show();                        }else{                            // 选择更新                            new AlertDialog.Builder(MainActivity.this)                                    .setTitle("版本更新")                                    .setMessage("是否要升级到最新版本")                                    .setPositiveButton("确定", new DialogInterface.OnClickListener() {                                        @Override                                        public void onClick(DialogInterface dialog, int which) {                                            updateVersion(version.getUrl());                                            dialog.dismiss();                                        }                                    })                                    .setNegativeButton("下次再说", new DialogInterface.OnClickListener() {                                        @Override                                        public void onClick(DialogInterface dialog, int which) {                                            dialog.dismiss();                                        }                                    })                                    .create().show();                        }                        } else {                            // 无可用更新                            Toast.makeText(MainActivity.this, "当前已经是最新版本", Toast.LENGTH_SHORT).show();                        }                    }                }                @Override                public void onError (Throwable ex,boolean isOnCallback){                    Log.i("------------", "onError: " + ex.getMessage());                }                @Override                public void onCancelled (CancelledException cex){                }                @Override                public void onFinished () {                }            });        }    /**     * 版本更新     */    private void updateVersion(String url) {        targetPath = targetPath + System.currentTimeMillis() + ".apk";        RequestParams params = new RequestParams(url);        // 设置下载保存路径        params.setSaveFilePath(targetPath);        // xutils的文件下载        x.http().get(params, new Callback.ProgressCallback<File>() {            @Override            public void onSuccess(File result) {                if (progressDialog.isShowing()) {                    progressDialog.dismiss();                }                installApk(result);            }            @Override            public void onError(Throwable ex, boolean isOnCallback) {                if (progressDialog.isShowing()) {                    progressDialog.dismiss();                }                Toast.makeText(MainActivity.this, "下载失败", Toast.LENGTH_SHORT).show();            }            @Override            public void onCancelled(CancelledException cex) {            }            @Override            public void onFinished() {            }            @Override            public void onWaiting() {            }            @Override            public void onStarted() {            }            @Override            public void onLoading(long total, long current, boolean isDownloading) {                if (isDownloading) {                    progressDialog.setMessage("正在下载...");                    progressDialog.show();                    progressDialog.setMax((int) total);                    progressDialog.setProgress((int) current);                }            }        });    }    /**     * 安装apk     */    private void installApk(File file) {        Intent intent = new Intent();        intent.setAction(Intent.ACTION_VIEW);        intent.addCategory("android.intent.category.DEFAULT");        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);        intent.setDataAndType(Uri.fromFile(file), "application/vnd.android.package-archive");        startActivity(intent);        android.os.Process.killProcess(android.os.Process.myPid());    }}