本文实例讲述了android内容提供者contentprovider用法。分享给大家供大家参考,具体如下:
personcontentprovider内容提供者类
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package com.ljq.db; import android.content.contentprovider; import android.content.contenturis; import android.content.contentvalues; import android.content.urimatcher; import android.database.cursor; import android.database.sqlite.sqlitedatabase; import android.net.uri; import android.text.textutils; /** * 内容提供者 * * 作用:统一数据访问方式,方便外部调用 * * @author jiqinlin * */ public class personcontentprovider extends contentprovider { // 数据集的mime类型字符串则应该以vnd.android.cursor.dir/开头 public static final string persons_type = "vnd.android.cursor.dir/person" ; // 单一数据的mime类型字符串应该以vnd.android.cursor.item/开头 public static final string persons_item_type = "vnd.android.cursor.item/person" ; public static final string authority = "com.ljq.provider.personprovider" ; // 主机名 /* 自定义匹配码 */ public static final int persons = 1; /* 自定义匹配码 */ public static final int person = 2 ; public static final uri persons_uri = uri.parse( "content://" + authority + "/person" ); private dbopenhelper dbopenhelper = null ; // urimatcher类用来匹配uri,使用match()方法匹配路径时返回匹配码 private static final urimatcher urimatcher; static { // 常量urimatcher.no_match表示不匹配任何路径的返回码 urimatcher = new urimatcher(urimatcher.no_match); // 如果match()方法匹配content://com.ljq.provider.personprovider/person路径,返回匹配码为persons urimatcher.adduri(authority, "person" , persons); // 如果match()方法匹配content://com.ljq.provider.personprovider/person/230路径,返回匹配码为person urimatcher.adduri(authority, "person/#" , person); } @override public boolean oncreate() { dbopenhelper = new dbopenhelper( this .getcontext()); return true ; } @override public uri insert(uri uri, contentvalues values){ sqlitedatabase db = dbopenhelper.getwritabledatabase(); long id = 0 ; switch (urimatcher.match(uri)) { case persons: id = db.insert( "person" , "name" , values); // 返回的是记录的行号,主键为int,实际上就是主键值 return contenturis.withappendedid(uri, id); case person: id = db.insert( "person" , "name" , values); string path = uri.tostring(); return uri.parse(path.substring( 0 , path.lastindexof( "/" ))+id); // 替换掉id default : throw new illegalargumentexception( "unknown uri " + uri); } } @override public int delete(uri uri, string selection, string[] selectionargs) { sqlitedatabase db = dbopenhelper.getwritabledatabase(); int count = 0 ; switch (urimatcher.match(uri)) { case persons: count = db.delete( "person" , selection, selectionargs); break ; case person: // 下面的方法用于从uri中解析出id,对这样的路径content://com.ljq.provider.personprovider/person/10 // 进行解析,返回值为10 long personid = contenturis.parseid(uri); string where = "id=" + personid; // 删除指定id的记录 where += !textutils.isempty(selection) ? " and (" + selection + ")" : "" ; // 把其它条件附加上 count = db.delete( "person" , where, selectionargs); break ; default : throw new illegalargumentexception( "unknown uri " + uri); } db.close(); return count; } @override public int update(uri uri, contentvalues values, string selection, string[] selectionargs) { sqlitedatabase db = dbopenhelper.getwritabledatabase(); int count = 0 ; switch (urimatcher.match(uri)) { case persons: count = db.update( "person" , values, selection, selectionargs); break ; case person: // 下面的方法用于从uri中解析出id,对这样的路径content://com.ljq.provider.personprovider/person/10 // 进行解析,返回值为10 long personid = contenturis.parseid(uri); string where = "id=" + personid; // 获取指定id的记录 where += !textutils.isempty(selection) ? " and (" + selection + ")" : "" ; // 把其它条件附加上 count = db.update( "person" , values, where, selectionargs); break ; default : throw new illegalargumentexception( "unknown uri " + uri); } db.close(); return count; } @override public string gettype(uri uri) { switch (urimatcher.match(uri)) { case persons: return persons_type; case person: return persons_item_type; default : throw new illegalargumentexception( "unknown uri " + uri); } } @override public cursor query(uri uri, string[] projection, string selection, string[] selectionargs, string sortorder) { sqlitedatabase db = dbopenhelper.getreadabledatabase(); switch (urimatcher.match(uri)) { case persons: return db.query( "person" , projection, selection, selectionargs, null , null , sortorder); case person: // 下面的方法用于从uri中解析出id,对这样的路径content://com.ljq.provider.personprovider/person/10 // 进行解析,返回值为10 long personid = contenturis.parseid(uri); string where = "id=" + personid; // 获取指定id的记录 where += !textutils.isempty(selection) ? " and (" + selection + ")" : "" ; // 把其它条件附加上 return db.query( "person" , projection, where, selectionargs, null , null , sortorder); default : throw new illegalargumentexception( "unknown uri " + uri); } } } |
文件清单
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<?xml version= "1.0" encoding= "utf-8" ?> <manifest xmlns:android= "http://schemas.android.com/apk/res/android" package = "com.ljq.sql" android:versioncode= "1" android:versionname= "1.0" > <application android:icon= "@drawable/icon" android:label= "@string/app_name" > <uses-library android:name= "android.test.runner" /> <activity android:name= ".sqlactivity" android:label= "@string/app_name" > <intent-filter> <action android:name= "android.intent.action.main" /> <category android:name= "android.intent.category.launcher" /> </intent-filter> </activity> <provider android:name= "com.ljq.db.personcontentprovider" android:authorities= "com.ljq.provider.personprovider" /> </application> <uses-sdk android:minsdkversion= "7" /> <instrumentation android:name= "android.test.instrumentationtestrunner" android:targetpackage= "com.ljq.sql" android:label= "tests for my app" /> </manifest> |
personcontentprovidertest内容提供者测试类
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package com.ljq.test; import android.content.contentresolver; import android.content.contentvalues; import android.database.cursor; import android.net.uri; import android.test.androidtestcase; import android.util.log; /** * 外部访问内容提供者 * * @author jiqinlin * */ public class personcontentprovidertest extends androidtestcase{ private static final string tag = "personcontentprovidertest" ; public void testsave() throws throwable{ contentresolver contentresolver = this .getcontext().getcontentresolver(); uri inserturi = uri.parse( "content://com.ljq.provider.personprovider/person" ); contentvalues values = new contentvalues(); values.put( "name" , "ljq" ); values.put( "phone" , "1350000009" ); uri uri = contentresolver.insert(inserturi, values); log.i(tag, uri.tostring()); } public void testupdate() throws throwable{ contentresolver contentresolver = this .getcontext().getcontentresolver(); uri updateuri = uri.parse( "content://com.ljq.provider.personprovider/person/1" ); contentvalues values = new contentvalues(); values.put( "name" , "linjiqin" ); contentresolver.update(updateuri, values, null , null ); } public void testfind() throws throwable{ contentresolver contentresolver = this .getcontext().getcontentresolver(); //uri uri = uri.parse("content://com.ljq.provider.personprovider/person"); uri uri = uri.parse( "content://com.ljq.provider.personprovider/person" ); cursor cursor = contentresolver.query(uri, null , null , null , "id asc" ); while (cursor.movetonext()){ int personid = cursor.getint(cursor.getcolumnindex( "id" )); string name = cursor.getstring(cursor.getcolumnindex( "name" )); string phone = cursor.getstring(cursor.getcolumnindex( "phone" )); log.i(tag, "personid=" + personid + ",name=" + name+ ",phone=" + phone); } cursor.close(); } public void testdelete() throws throwable{ contentresolver contentresolver = this .getcontext().getcontentresolver(); uri uri = uri.parse( "content://com.ljq.provider.personprovider/person/1" ); contentresolver.delete(uri, null , null ); } } |
希望本文所述对大家android程序设计有所帮助。