本文转自：http://yaku2688.iteye.com/blog/1185364

ContentProvider数据共享

1.首先在AndroidManifest.xml文件中添加对外暴露的数据共享接口Content

Xml代码
  1. <providerandroid:name=".UserProvider"android:authorities="com.yaku.ContentProvider.userprovider"/>

ContentProvider采用了authorities（主机名/域名）对它进行唯一标识，authorities 就是他的域名

2.Url解析
content://com.yaku.ContentProvider.userprovider/user/2
【content://】 Android定义的内容提供都的Schema
【com.yaku.ContentProvider.userprovider】 主机名或者authorities
【user】 路径
【2】 ID

示例代码：

数据结构User.java：

Java代码
  1. packagecom.yaku.pojo;
  3. publicclassUser{
  4. privateintid;
  5. privateStringname;
  6. privateintage;
  8. publicUser(intid,Stringname,intage){
  9. super();
  10. this.id=id;
  11. this.name=name;
  12. this.age=age;
  13. }
  14. publicintgetId(){
  15. returnid;
  16. }
  17. publicvoidsetId(intid){
  18. this.id=id;
  19. }
  20. publicStringgetName(){
  21. returnname;
  22. }
  23. publicvoidsetName(Stringname){
  24. this.name=name;
  25. }
  26. publicintgetAge(){
  27. returnage;
  28. }
  29. publicvoidsetAge(intage){
  30. this.age=age;
  31. }
  32. @Override
  33. publicStringtoString(){
  34. return"User[age="+age+",id="+id+",name="+name+"]";
  35. }
  36. }

数据库操作DBOpenHelper.java：

Java代码
  1. packagecom.yaku.db;
  3. importandroid.content.Context;
  4. importandroid.database.sqlite.SQLiteDatabase;
  5. importandroid.database.sqlite.SQLiteOpenHelper;
  7. publicclassDBOpenHelperextendsSQLiteOpenHelper{
  8. privatestaticfinalStringDBNAME="yaku.db";//数据库名称
  9. privatestaticfinalintDBVER=1;//数据库版本
  11. publicDBOpenHelper(Contextcontext){
  12. super(context,DBNAME,null,DBVER);
  13. }
  15. @Override
  16. publicvoidonCreate(SQLiteDatabasedb){
  17. Stringsql="CREATETABLEuser(useridintegerprimarykeyautoincrement,namevarchar(20),ageinteger)";
  18. db.execSQL(sql);//执行有更改的sql语句
  19. }
  21. @Override
  22. publicvoidonUpgrade(SQLiteDatabasedb,intarg1,intarg2){
  23. db.execSQL("DROPTABLEIFEXISTSuser");
  24. onCreate(db);
  25. }
  27. }

对外共享处理类ContentProviderUser.java：

Java代码
  1. packagecom.yaku.ContentProvider;
  3. importcom.yaku.db.DBOpenHelper;
  5. importandroid.content.ContentProvider;
  6. importandroid.content.ContentUris;
  7. importandroid.content.ContentValues;
  8. importandroid.content.UriMatcher;
  9. importandroid.database.Cursor;
  10. importandroid.database.sqlite.SQLiteDatabase;
  11. importandroid.net.Uri;
  13. publicclassContentProviderUserextendsContentProvider{
  14. privateDBOpenHelperdbOpenHelper;
  15. //常量UriMatcher.NO_MATCH表示不匹配任何路径的返回码
  16. privatestaticfinalUriMatcherMATCHER=newUriMatcher(UriMatcher.NO_MATCH);
  17. privatestaticfinalintUSERS=1;
  18. privatestaticfinalintUSER=2;
  19. static{
  20. //如果match()方法匹配content://com.yaku.ContentProvider.userprovider/user路径，返回匹配码为1
  21. MATCHER.addURI("com.yaku.ContentProvider.userprovider","user",USERS);
  22. //如果match()方法匹配content://com.yaku.ContentProvider.userprovider/user/123路径，返回匹配码为2
  23. MATCHER.addURI("com.yaku.ContentProvider.userprovider","user/#",USER);//#号为通配符
  24. }
  25. @Override
  26. publicintdelete(Uriuri,Stringselection,String[]selectionArgs){
  27. SQLiteDatabasedb=dbOpenHelper.getWritableDatabase();
  28. intcount=0;
  29. switch(MATCHER.match(uri)){
  30. caseUSERS:
  31. count=db.delete("user",selection,selectionArgs);
  32. returncount;
  33. caseUSER:
  34. //ContentUris类用于获取Uri路径后面的ID部分
  35. longid=ContentUris.parseId(uri);
  36. Stringwhere="userid="+id;
  37. if(selection!=null&&!"".equals(selection)){
  38. where=selection+"and"+where;
  39. }
  40. count=db.delete("user",where,selectionArgs);
  41. returncount;
  42. default:
  43. thrownewIllegalArgumentException("UnkwonUri:"+uri.toString());
  44. }
  45. }
  47. /**
  48. *该方法用于返回当前Url所代表数据的MIME类型。
  49. *如果操作的数据属于集合类型，那么MIME类型字符串应该以vnd.android.cursor.dir/开头
  50. *如果要操作的数据属于非集合类型数据，那么MIME类型字符串应该以vnd.android.cursor.item/开头
  51. */
  52. @Override
  53. publicStringgetType(Uriuri){
  54. switch(MATCHER.match(uri)){
  55. caseUSERS:
  56. return"vnd.android.cursor.dir/user";
  58. caseUSER:
  59. return"vnd.android.cursor.item/user";
  61. default:
  62. thrownewIllegalArgumentException("UnkwonUri:"+uri.toString());
  63. }
  64. }
  66. @Override
  67. publicUriinsert(Uriuri,ContentValuesvalues){
  68. SQLiteDatabasedb=dbOpenHelper.getWritableDatabase();
  69. switch(MATCHER.match(uri)){
  70. caseUSERS:
  71. longrowid=db.insert("user","name",values);
  72. UriinsertUri=ContentUris.withAppendedId(uri,rowid);//得到代表新增记录的Uri
  73. this.getContext().getContentResolver().notifyChange(uri,null);
  74. returninsertUri;
  76. default:
  77. thrownewIllegalArgumentException("UnkwonUri:"+uri.toString());
  78. }
  79. }
  81. @Override
  82. publicbooleanonCreate(){
  83. this.dbOpenHelper=newDBOpenHelper(this.getContext());
  84. returnfalse;
  85. }
  87. @Override
  88. publicCursorquery(Uriuri,String[]projection,Stringselection,String[]selectionArgs,
  89. StringsortOrder){
  90. SQLiteDatabasedb=dbOpenHelper.getReadableDatabase();
  91. switch(MATCHER.match(uri)){
  92. caseUSERS:
  93. returndb.query("user",projection,selection,selectionArgs,null,null,sortOrder);
  94. caseUSER:
  95. longid=ContentUris.parseId(uri);
  96. Stringwhere="userid="+id;
  97. if(selection!=null&&!"".equals(selection)){
  98. where=selection+"and"+where;
  99. }
  100. returndb.query("user",projection,where,selectionArgs,null,null,sortOrder);
  101. default:
  102. thrownewIllegalArgumentException("UnkwonUri:"+uri.toString());
  103. }
  104. }
  106. @Override
  107. publicintupdate(Uriuri,ContentValuesvalues,Stringselection,String[]selectionArgs){
  108. SQLiteDatabasedb=dbOpenHelper.getWritableDatabase();
  109. intcount=0;
  110. switch(MATCHER.match(uri)){
  111. caseUSERS:
  112. count=db.update("person",values,selection,selectionArgs);
  113. returncount;
  114. caseUSER:
  115. longid=ContentUris.parseId(uri);
  116. Stringwhere="userid="+id;
  117. if(selection!=null&&!"".equals(selection)){
  118. where=selection+"and"+where;
  119. }
  120. count=db.update("user",values,where,selectionArgs);
  121. returncount;
  122. default:
  123. thrownewIllegalArgumentException("UnkwonUri:"+uri.toString());
  124. }
  125. }
  126. }

单元测试类（在另一个应用中）：

Java代码
  1. packagecom.yaku.ContentProvider;
  3. importandroid.content.ContentResolver;
  4. importandroid.content.ContentValues;
  5. importandroid.database.Cursor;
  6. importandroid.net.Uri;
  7. importandroid.test.AndroidTestCase;
  8. importandroid.util.Log;
  10. /**
  11. *对ContentProvider工程中的ContentProviderActivity进行单元测试
  12. */
  13. publicclassContentProviderActivityTestextendsAndroidTestCase{
  14. privatestaticfinalStringTAG="ContentProvider";
  15. //往内容提供者添加数据
  16. publicvoidtestInsert()throwsThrowable{
  17. ContentResolvercontentResolver=this.getContext().getContentResolver();
  18. UriinsertUri=Uri.parse("content://com.yaku.ContentProvider.userprovider/user");
  19. ContentValuesvalues=newContentValues();
  20. values.put("name","道长");
  21. values.put("age",86);
  22. Uriuri=contentResolver.insert(insertUri,values);
  23. Log.i(TAG,uri.toString());
  24. }
  26. //更新内容提供者中的数据
  27. publicvoidtestUpdate()throwsThrowable{
  28. ContentResolvercontentResolver=this.getContext().getContentResolver();
  29. UriupdateUri=Uri.parse("content://com.yaku.ContentProvider.userprovider/user/1");
  30. ContentValuesvalues=newContentValues();
  31. values.put("name","青眉道长");
  32. contentResolver.update(updateUri,values,null,null);
  33. }
  35. //从内容提供者中删除数据
  36. publicvoidtestDelete()throwsThrowable{
  37. ContentResolvercontentResolver=this.getContext().getContentResolver();
  38. UrideleteUri=Uri.parse("content://com.yaku.ContentProvider.userprovider/user/1");
  39. contentResolver.delete(deleteUri,null,null);
  40. }
  42. //获取内容提供者中的数据
  43. publicvoidtestFind()throwsThrowable{
  44. ContentResolvercontentResolver=this.getContext().getContentResolver();
  45. UriselectUri=Uri.parse("content://com.yaku.ContentProvider.userprovider/user");
  46. Cursorcursor=contentResolver.query(selectUri,null,null,null,"useriddesc");
  47. while(cursor.moveToNext()){
  48. intid=cursor.getInt(cursor.getColumnIndex("userid"));
  49. Stringname=cursor.getString(cursor.getColumnIndex("name"));
  50. intage=cursor.getInt(cursor.getColumnIndex("age"));
  51. Log.i(TAG,"id="+id+",name="+name+",age="+age);
  52. }
  53. }
  55. }

监听数据的变化：

Java代码
  1. <SPANstyle="FONT-SIZE:medium">packagecom.yaku.ContentProvider;
  3. importandroid.content.ContentResolver;
  4. importandroid.content.ContentValues;
  5. importandroid.database.Cursor;
  6. importandroid.net.Uri;
  7. importandroid.test.AndroidTestCase;
  8. importandroid.util.Log;
  10. /**
  11. *监听数据变化
  12. */
  13. publicclassOtherContentProviderTestextendsAndroidTestCase{
  14. privatestaticfinalStringTAG="OtherContentProvider";
  16. @Override
  17. publicvoidonCreate(BundlesavedInstanceState){
  18. super.onCreate(savedInstanceState);
  19. setContentView(R.layout.main);
  21. UriinsertUri=Uri.parse("content://com.yaku.ContentProvider.userprovider/user");
  22. ContentResolvercontentResolver=this.getContentResolver();
  23. //对指定uri进行监听，如果该uri代表的数据发生变化，就会调用PersonObserver中的onChange()
  24. contentResolver.registerContentObserver(insertUri,true,newPersonObserver(newHandler()));
  25. }
  27. privatefinalclassPersonObserverextendsContentObserver{
  28. publicPersonObserver(Handlerhandler){
  29. super(handler);
  30. }
  32. @Override
  33. publicvoidonChange(booleanselfChange){
  34. ContentResolvercontentResolver=getContentResolver();
  35. UriselectUri=Uri.parse("content://com.yaku.ContentProvider.userprovider/user");
  36. Cursorcursor=contentResolver.query(selectUri,null,null,null,"useriddesc");
  37. while(cursor.moveToNext()){
  38. intid=cursor.getInt(cursor.getColumnIndex("userid"));
  39. Stringname=cursor.getString(cursor.getColumnIndex("name"));
  40. intage=cursor.getInt(cursor.getColumnIndex("age"));
  41. Log.i(TAG,"id="+id+",name="+name+",age="+age);
  42. }
  43. }
  44. }
  45. }
  46. </SPAN>

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