远程Service及Sqlite示例

1. 先创建RemoteServiceServer 远程Service服务端
2. 新建一个aidl，并命名为IMyAidlInterface.aidl，文件里的代码如下：

// IMyAidlInterface.aidl
// 在新建的IMyAidlInterface.aidl里声明需要与Activity进行通信的方法
package com.dlrj.remoteserviceserver;
import com.dlrj.remoteserviceserver.StudentInfo;

// Declare any non-default types here with import statements

interface IMyAidlInterface {
    void AIDL_Service();
    void setStudentInfos(in List studendNames);
    void addStudentInfo(in StudentInfo studentInfo);
    List getAllStudentInfos();
    StudentInfo getStudentInfo(int id);
    int getStudentId(String studentName);
    int delete(int id, String name, String gender, int grade, int class_);
    List queryByCondition(int id, String name, String gender, int grade, int class_);
}

//AIDL中支持以下的数据类型
//1. 基本数据类型
//2. String 和CharSequence
//3. List 和 Map ,List和Map 对象的元素必须是AIDL支持的数据类型;
//4. AIDL自动生成的接口（需要导入-import）
//5. 实现android.os.Parcelable 接口的类（需要导入-import)

由于我们示例中传输的数据对象继承Parcelable，所以需要另外新建一个aidl，命名为StudentInfo.aidl，并且需要定义StudentInfo为parcelable类型，注意parcelable在aidl中必须小写

// StudentInfo.aidl
package com.dlrj.remoteserviceserver;

// Declare any non-default types here with import statements

parcelable StudentInfo;

StudentInfo代码实现如下：

package com.dlrj.remoteserviceserver;

import android.os.Parcel;
import android.os.Parcelable;

public class StudentInfo implements Parcelable {
    private String name;  //姓名

    private int id;   //学号

    private String gender; //性别

    private int grade; //年级

    private int class_;  //班级

    public StudentInfo() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public int getGrade() {
        return grade;
    }

    public void setGrade(int grade) {
        this.grade = grade;
    }

    public int getClass_() {
        return class_;
    }

    public void setClass_(int class_) {
        this.class_ = class_;
    }


//    @Override
//    public String toString() {
//        return "book name：" + name;
//    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(this.name);
        dest.writeInt(id);
        dest.writeString(gender);
        dest.writeInt(grade);
        dest.writeInt(class_);
    }

    public void readFromParcel(Parcel dest) {
        name = dest.readString();
        id = dest.readInt();
        gender = dest.readString();
        grade = dest.readInt();
        class_ = dest.readInt();
    }

    protected StudentInfo(Parcel in) {
//        this.name = in.readString();
//        this.id = in.readInt();
//        this.gender = in.readString();
//        this.grade = in.readInt();
//        this.class_ = in.readInt();
        this.readFromParcel(in);
    }

    public static final Creator CREATOR = new Creator() {
        @Override
        public StudentInfo createFromParcel(Parcel source) {
            return new StudentInfo(source);
        }

        @Override
        public StudentInfo[] newArray(int size) {
            return new StudentInfo[size];
        }
    };
}

1. 新建一个Service，并命名为MyService，并在Service里面实现对sqlite数据库的操作，代码实现如下

package com.dlrj.remoteserviceserver;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

import java.util.ArrayList;
import java.util.List;

public class MyService extends Service {

    private static final String LOG_PRINT_TAG = "MyService";

//    private List studentNames = new ArrayList();

    private DBHelper dbHelper = null;

    IMyAidlInterface.Stub mBinder = new IMyAidlInterface.Stub() {
        @Override
        public void AIDL_Service() throws RemoteException {
            Log.e(LOG_PRINT_TAG, "客户端调用了IMyAidlInterface.Stub的AIDL_Service方法");
            if (dbHelper == null) {
                dbHelper = new DBHelper(getApplicationContext());
            }
        }

        @Override
        public void setStudentInfos(@NonNull List studendNames_) {
//            studentNames = studendNames_;
        }

        @Override
        public void addStudentInfo(@NonNull StudentInfo studentInfo) throws RemoteException {
            dbHelper.update(studentInfo);
        }

        @Override
        public List getAllStudentInfos() throws RemoteException {
            return dbHelper.getStudentInfoList();
        }


        @Override
        public StudentInfo getStudentInfo(int id) {
            ArrayList studentInfoList = dbHelper.getStudentInfoList();
            if (studentInfoList.isEmpty()) {
                return null;
            }
            if (id < 0 || id >= studentInfoList.size()) {
                return null;
            }
            return studentInfoList.get(id);
        }

        @Override
        public int getStudentId(String studentName) {
            ArrayList studentInfoList = dbHelper.getStudentInfoList();
            if (studentInfoList.isEmpty()) {
                return -1;
            }
            if (studentName == null || studentName.trim().length() < 1) {
                return -1;
            }
            for (int i = 0; i < studentInfoList.size(); i++) {
                StudentInfo studentInfo = studentInfoList.get(i);
                if (studentInfo != null && studentInfo.getName() == studentName) {
                    return i;
                }
            }
            return -1;
        }

        @Override
        public int delete(int id, String name, String gender, int grade, int class_) throws RemoteException {
            return dbHelper.delete(id, name, gender, grade, class_);
        }

        @Override
        public List queryByCondition(int id, String name, String gender, int grade, int class_) throws RemoteException {
            return dbHelper.queryByCondition(id, name, gender, grade, class_);
        }
    };

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        Log.e(LOG_PRINT_TAG, "执行了onBind()");
        return mBinder;
    }

    @Override
    public boolean onUnbind(Intent intent) {
        Log.e(LOG_PRINT_TAG, "执行了onUnbind()");
        return super.onUnbind(intent);
    }

    @Override
    public void onCreate() {
        super.onCreate();
        Log.e(LOG_PRINT_TAG, "执行了onCreate()");
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.e(LOG_PRINT_TAG, "执行了onStartCommand()" + flags + "  " + startId);
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        if (dbHelper != null) {
            dbHelper.close();
        }
        Log.e(LOG_PRINT_TAG, "执行了onDestroy()");
    }
}

在AndroidManifest.xml里添加下面代码

    android:process=":remote"
    android:exported="true">
    
        
    

android:process=":remote"  一定要设置为remote  远程Service 其他应用也能通过名字，启动并绑定我们的远程服务

1. 新建一个数据库管理类DBHelper，代码如下

package com.dlrj.remoteserviceserver;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

import androidx.annotation.Nullable;

import java.util.ArrayList;
import java.util.Vector;

public class DBHelper extends SQLiteOpenHelper {

    private static final String LOG_PRINT_TAG = "MyService";

    private static final String TABLE_NAME = "Student";

    //T_R table_row
    public static final String T_R_NAME = "name";
    public static final String T_R_ID = "id";
    public static final String T_R_GENDER = "gender";
    public static final String T_R_GRADE = "grade";
    public static final String T_R_CLASS = "class_";

    public static final String CREATE_BOOK = "create table " + TABLE_NAME + " ( "
            + T_R_ID + " integer primary key autoincrement,"
            + T_R_GENDER + " text,"
            + T_R_GRADE + " integer,"
            + T_R_CLASS + " integer,"
            + T_R_CLASS + " text)";

    private static final int VERSION = 1;

    private ArrayList studentInfoList = null;

    private int lastMissId = 0;  //上一个缺失的学号

    public DBHelper(@Nullable Context context) {
        super(context, TABLE_NAME, null, VERSION);
        studentInfoList = new ArrayList();
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(CREATE_BOOK);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("drop table if exists " + TABLE_NAME);  //删除表
        onCreate(db);  //重新创建表
    }

    
    private long insert(StudentInfo studentInfo, SQLiteDatabase db, int id) {
        Log.e(LOG_PRINT_TAG, "insert");
        boolean isGet = false;
        if (db == null) {
            db = this.getWritableDatabase();
            isGet = true;
        }
        ContentValues values = new ContentValues();
        if (id > 0) {
            values.put(T_R_ID, id);
        }
        values.put(T_R_NAME,studentInfo.getName());
        values.put(T_R_GENDER,studentInfo.getGender());
        values.put(T_R_GRADE,studentInfo.getGrade());
        values.put(T_R_CLASS,studentInfo.getClass_());
        long insertnum = 0;
        if (id > 0) {
            insertnum = db.insert(TABLE_NAME,T_R_ID,values);
        } else {
            insertnum = db.insert(TABLE_NAME,null,values);
        }
        Log.e(LOG_PRINT_TAG, "insert insertnum = " + insertnum);
        if (insertnum > 0) {
            this.queryAll();
        }
        return insertnum;
    }

    
    public int update(StudentInfo studentInfo) {
        Log.e(LOG_PRINT_TAG, "update " + studentInfo.toString());
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(T_R_NAME,studentInfo.getName());
        values.put(T_R_GENDER,studentInfo.getGender());
        values.put(T_R_GRADE,studentInfo.getGrade());
        values.put(T_R_CLASS,studentInfo.getClass_());
        int effectRowNum = db.update(TABLE_NAME, values, T_R_NAME + "=?", new String[]{ studentInfo.getName()});

        Log.e(LOG_PRINT_TAG, "update effectRowNum = " + effectRowNum);
        if (effectRowNum > 0) {  //如果更新表失败
            this.queryAll();
        } else {  //则进行插入表操作
            findIdInfos();  //查找缺失的id信息
            effectRowNum = (int) this.insert(studentInfo, db, lastMissId);  //插入的位置，如果为0是，是往上一条后面插入数据  返回影响的行数 行数大于0，插入表成功
        }
        return effectRowNum;
    }

    
    private void findIdInfos() {
        Log.e(LOG_PRINT_TAG, "findIdInfos");
        ArrayList list = this.getStudentInfoList();
        lastMissId = 0;
        if (list.size() > 0) {
            for (int i = 0; i < list.size(); i++) {
                StudentInfo studentInfo = list.get(i);
                if ((i + 1) != studentInfo.getId()) {
                    lastMissId = i + 1;
                    Log.e(LOG_PRINT_TAG, "findIdInfos lastMissId = " + lastMissId);
                    break;
                }
            }
        }
    }

    
    public int delete(int id, String name, String gender, int grade, int class_) {
        SQLiteDatabase db = this.getWritableDatabase();
        StringBuilder conditions = new StringBuilder();
        Vector vecConditionDatas = new Vector();
        if (id > 0) {
            conditions.append(T_R_ID + "=?");
            vecConditionDatas.add("" + id);
        }
        if (name != null && name.length() > 0) {
            if (conditions.length() > 0) {
                conditions.append("," + T_R_NAME + "=?");
            } else {
                conditions.append(T_R_NAME + "=?");
            }
            vecConditionDatas.add(name);
        }
        if (gender != null && gender.length() > 0) {
            if (conditions.length() > 0) {
                conditions.append("," + T_R_GENDER + "=?");
            } else {
                conditions.append(T_R_GENDER + "=?");
            }
            vecConditionDatas.add(gender);
        }
        if (grade > 0) {
            if (conditions.length() > 0) {
                conditions.append("," + T_R_GRADE + "=?");
            } else {
                conditions.append(T_R_GRADE + "=?");
            }
            vecConditionDatas.add("" + grade);
        }
        if (class_ > 0) {
            if (conditions.length() > 0) {
                conditions.append("," + T_R_CLASS + "=?");
            } else {
                conditions.append(T_R_CLASS + "=?");
            }
            vecConditionDatas.add("" + class_);
        }
        Log.e(LOG_PRINT_TAG, "queryByCondition conditions = " + conditions);
        String[] conditionDatas = new String[vecConditionDatas.size()];
        for (int i = 0; i < vecConditionDatas.size(); i++) {
            conditionDatas[i] = vecConditionDatas.get(i);
        }
        int effectRowNum = db.delete(TABLE_NAME, conditions.toString(), conditionDatas);
        if (effectRowNum > 0) {
            this.queryAll();
        }
        return effectRowNum;
    }

    
    public ArrayList queryByCondition(int id, String name, String gender, int grade, int class_) {
        SQLiteDatabase db = this.getReadableDatabase();
        StringBuilder conditions = new StringBuilder();  //精确查找条件
        StringBuilder conditions2 = new StringBuilder();  //模糊查找条件
        Vector vecConditionDatas = new Vector();
        if (id > 0) {
            conditions.append(T_R_ID + "=?");
            conditions2.append(T_R_ID + " LIKE ?");
            vecConditionDatas.add("" + id);
        }
        if (name != null && name.length() > 0) {
            if (conditions.length() > 0) {
                conditions.append("," + T_R_NAME + "=?");
                conditions2.append("," + T_R_NAME + " LIKE ?");
            } else {
                conditions.append(T_R_NAME + "=?");
                conditions2.append(T_R_NAME + " LIKE ?");
            }
            vecConditionDatas.add(name);
        }
        if (gender != null && gender.length() > 0) {
            if (conditions.length() > 0) {
                conditions.append("," + T_R_GENDER + "=?");
                conditions2.append("," + T_R_GENDER + " LIKE ?");
            } else {
                conditions.append(T_R_GENDER + "=?");
                conditions2.append(T_R_GENDER + " LIKE ?");
            }
            vecConditionDatas.add(gender);
        }
        if (grade > 0) {
            if (conditions.length() > 0) {
                conditions.append("," + T_R_GRADE + "=?");
                conditions2.append("," + T_R_GRADE + " LIKE ?");
            } else {
                conditions.append(T_R_GRADE + "=?");
                conditions2.append(T_R_GRADE + " LIKE ?");
            }
            vecConditionDatas.add("" + grade);
        }
        if (class_ > 0) {
            if (conditions.length() > 0) {
                conditions.append("," + T_R_CLASS + "=?");
                conditions2.append("," + T_R_CLASS + " LIKE ?");
            } else {
                conditions.append(T_R_CLASS + "=?");
                conditions2.append(T_R_CLASS + " LIKE ?");
            }
            vecConditionDatas.add("" + class_);
        }
        Log.e(LOG_PRINT_TAG, "queryByCondition conditions = " + conditions);
        String[] conditionDatas = new String[vecConditionDatas.size()];
        String[] conditionDatas2 = new String[vecConditionDatas.size()];
        for (int i = 0; i < vecConditionDatas.size(); i++) {
            conditionDatas[i] = vecConditionDatas.get(i);
            conditionDatas2[i] = "%" + vecConditionDatas.get(i) + "%";
        }
        ArrayList studentInfos = new ArrayList();
        Cursor cursor = null;
        cursor = db.query(TABLE_NAME, new String[]{T_R_ID,T_R_NAME,T_R_GENDER, T_R_GRADE, T_R_CLASS},
                conditions.toString(), conditionDatas, null, null, null);  //精确查找
        if (cursor.getCount() < 1) {
            cursor = db.query(TABLE_NAME, new String[]{T_R_ID,T_R_NAME,T_R_GENDER, T_R_GRADE, T_R_CLASS}, conditions2.toString(),
                    conditionDatas2, null, null, null);  //模糊查找
        }

        cursor.moveToFirst();
        while (!cursor.isAfterLast()) {
            int id_=cursor.getInt(0);
            String name_=cursor.getString(1);
            String gender_ =cursor.getString(2);
            int grade_ = cursor.getInt(3);
            int class__ = cursor.getInt(4);
            StudentInfo studentInfo = new StudentInfo();
            studentInfo.setId(id_);
            studentInfo.setName(name_);
            studentInfo.setGender(gender_);
            studentInfo.setGrade(grade_);
            studentInfo.setClass_(class__);
            studentInfos.add(studentInfo);
            // do something useful with these
            cursor.moveTonext();
        }
        cursor.close();
        return studentInfos;
    }

    
    public void queryAll() {
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.query(TABLE_NAME, new String[]{T_R_ID,T_R_NAME,T_R_GENDER, T_R_GRADE, T_R_CLASS},
                null, null, null, null, null);
        cursor.moveToFirst();
        studentInfoList.clear();
        while (!cursor.isAfterLast()) {
            int id=cursor.getInt(0);
            String name=cursor.getString(1);
            String gender =cursor.getString(2);
            int grade = cursor.getInt(3);
            int class_ = cursor.getInt(4);
            StudentInfo studentInfo = new StudentInfo();
            studentInfo.setId(id);
            studentInfo.setName(name);
            studentInfo.setGender(gender);
            studentInfo.setGrade(grade);
            studentInfo.setClass_(class_);
            studentInfoList.add(studentInfo);
            // do something useful with these
            cursor.moveTonext();
        }
        cursor.close();
    }

    
    public void close() {
        SQLiteDatabase db = this.getReadableDatabase();
        db.close();
    }

    
    public ArrayList getStudentInfoList() {
        if (this.studentInfoList.size() == 0) {
            this.queryAll();
        }
        return this.studentInfoList;
    }
}

1. 新建一个名为RemoveServiceClient的项目，做为调用远程Service的工程

把RemoteServiceServer中创建的aidl拷贝到RemoveServiceClient项目中，

并将StudentInfo，RemoteServiceServer对应的目录下，在RemoveServiceClient代码目录生成同样的目录，并拷贝StudentInfo在当前目录下

1. 在RemoveServiceClient的MainActivity中创建一个服务连接

private IMyAidlInterface myService = null;

private ServiceConnection connection = new ServiceConnection() {

    @Override
    public void onServiceConnected(ComponentName name, IBinder service) {
        myService = IMyAidlInterface.Stub.asInterface(service);
        try {
            myService.AIDL_Service();
            MainActivity.this.setData();
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onServiceDisconnected(ComponentName name) {

    }
};

在MainActivity的OnCreate中创建并绑定远程服务

if (myService == null) {
    //通过Intent指定服务端的服务名称和所在包，与远程Service进行绑定
    //参数与服务器端的action要一致,即"服务器包名.aidl接口文件名"
    Intent intent = new Intent("com.dlrj.remoteserviceserver.IMyAidlInterface");

    //Android5.0后无法只通过隐式Intent绑定远程Service
    //需要通过setPackage()方法指定包名
    intent.setPackage("com.dlrj.remoteserviceserver");

    //绑定服务,传入intent和ServiceConnection对象
    bindService(intent, connection, Context.BIND_AUTO_CREATE);
}

这样，使用远程Service，并在Service中使用Sqlite保存数据的示例就好了。