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
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
<?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
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。
更多android内容提供者contentprovider用法实例分析。