[javase][json] org.codehaus.jackson的使用

PackageInfo.java

package test_2013_4_17;/** *  * @ClassName Packages *  * @Project egame.server.open.biz *  * @Author yuchao *  * @Create Date  2013-4-17 *  */public class PackageInfo {    private String package_name;    private String version;    /**     * @return the package_name     */    public String getPackage_name() {        return package_name;    }    /**     * @param package_name the package_name to set     */    public void setPackage_name(String package_name) {        this.package_name = package_name;    }    /**     * @return the version     */    public String getVersion() {        return version;    }    /**     * @param version the version to set     */    public void setVersion(String version) {        this.version = version;    }@Overridepublic String toString() {return "PackageInfo [package_name=" + package_name + ", version="+ version +"]";}    }

TestJson.java

package test_2013_4_17;import java.util.Iterator;import java.util.List;import java.util.Map;import java.util.Set;import org.codehaus.jackson.JsonParser;import org.codehaus.jackson.map.ObjectMapper;import org.codehaus.jackson.type.TypeReference;public class TestJson {public static void main(String[] args) throws Exception {testJsonToObject();testJsonToList();testJsonToMap();testJsonMapInList();    }/** * json字符串转换成普通对象 */private static void testJsonToObject() throws Exception{String jsonStr = "{'package_name':'愤怒的小鸟','version':'1.01'}";ObjectMapper mapper = new ObjectMapper();//允许键值对的引号为单引号,否则只能为双引号mapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);PackageInfo packageInfo = mapper.readValue(jsonStr, PackageInfo.class);System.out.println(packageInfo);}/** * json字符串转换成List */private static void testJsonToList() throws Exception{String jsonStr = "[{'package_name':'愤怒的小鸟','version':'1.01'}" +",{'package_name':'愤怒的小鸟','version':'1.01'}]";ObjectMapper mapper = new ObjectMapper();mapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);//List<PackageInfo> packageInfos = mapper.readValue(jsonStr, List.class);List<PackageInfo> packageInfos = mapper.readValue(jsonStr,new TypeReference<List<PackageInfo>>(){ });System.out.println(packageInfos);}/** * json字符串转换成Map  */private static void testJsonToMap() throws Exception{String jsonStr = "{'xiaoniao':'1.01','360':'2.2'}";ObjectMapper mapper = new ObjectMapper();mapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);//Map map = mapper.readValue(jsonStr, Map.class);Map<String,String> map = mapper.readValue(jsonStr,new TypeReference<Map<String,String>>(){ });Set<String> set = map.keySet();Iterator<String> it = set.iterator();while (it.hasNext()) {String str = (String) it.next();System.out.println("key:"+str+", "+"value:"+map.get(str));}}/** * 转换这种格式的json字符串到一个List<Map>对象 * [{'com.tencent.mm.apk':'0'},{'com.qihoo360.mobilesafe.apk':'1'}] */private static void testJsonMapInList() throws Exception{String jsonStr = "[{'xiaoniao':'1.01'},{'360':'2.2'}]";ObjectMapper mapper = new ObjectMapper();mapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);//下面两种都可以//List<Map<String,String>> list = mapper.readValue(jsonStr, List.class);List<Map<String,String>> list = mapper.readValue(jsonStr,new TypeReference<List<Map<String,String>>>(){ });for(Map<String, String> map : list){Set<String> set = map.keySet();Iterator<String> it = set.iterator();while (it.hasNext()) {String str = (String) it.next();System.out.println("key:"+str+", "+"value:"+map.get(str));}}}}