Json 转换地图<;字符串,字符串>;到波乔
我一直在关注Jackson,但似乎我必须将映射转换为JSON,然后将生成的JSON转换为POJOJson 转换地图<;字符串,字符串>;到波乔,json,dictionary,jackson,pojo,Json,Dictionary,Jackson,Pojo,我一直在关注Jackson,但似乎我必须将映射转换为JSON,然后将生成的JSON转换为POJO 有没有办法将映射直接转换为POJO?是的,完全可以避免中间转换为JSON。使用像这样的深度复制工具,可以将贴图直接转换为POJO。下面是一个简单的例子: 示例POJO: public class MyPojo implements Serializable { private static final long serialVersionUID = 1L; private Stri
有没有办法将映射直接转换为POJO?是的,完全可以避免中间转换为JSON。使用像这样的深度复制工具,可以将贴图直接转换为POJO。下面是一个简单的例子: 示例POJO:
public class MyPojo implements Serializable {
private static final long serialVersionUID = 1L;
private String id;
private String name;
private Integer age;
private Double savings;
public MyPojo() {
super();
}
// Getters/setters
@Override
public String toString() {
return String.format(
"MyPojo[id = %s, name = %s, age = %s, savings = %s]", getId(),
getName(), getAge(), getSavings());
}
}
示例转换代码:
public class CopyTest {
@Test
public void testCopyMapToPOJO() throws Exception {
final Map<String, String> map = new HashMap<String, String>(4);
map.put("id", "5");
map.put("name", "Bob");
map.put("age", "23");
map.put("savings", "2500.39");
map.put("extra", "foo");
final DozerBeanMapper mapper = new DozerBeanMapper();
final MyPojo pojo = mapper.map(map, MyPojo.class);
System.out.println(pojo);
}
}
公共类CopyTest{
@试验
public void testCopyMapToPOJO()引发异常{
最终映射=新的HashMap(4);
地图放置(“id”、“5”);
地图。放置(“名称”、“鲍勃”);
地图放置(“年龄”、“23”);
map.put(“储蓄”、“2500.39”);
地图放置(“额外”、“foo”);
最终DozerBeanMapper=新DozerBeanMapper();
final-MyPojo-pojo=mapper.map(map,MyPojo.class);
系统输出打印LN(pojo);
}
}
输出:
MyPojo[id=5,name=Bob,年龄=23,储蓄=2500.39]
注意:如果您将源映射更改为
map
,则可以复制任意深度嵌套的属性(使用map
只能获得一个级别)。使用Jackson也可以实现这一点。(自从您考虑使用jackson后,它似乎更舒适了)
使用ObjectMapper的方法:
无需转换为JSON字符串或其他内容;直接转换速度要快得多。具有以下功能的解决方案:
我测试了Jackson和BeanUtils,发现BeanUtils速度更快。
在我的机器(Windows8.1,JDK1.7)中,我得到了这个结果
BeanUtils t2-t1 = 286
Jackson t2-t1 = 2203
公共类MainMapToPOJO{
公共静态最终整数循环最大计数=1000;
公共静态void main(字符串[]args){
Map Map=newhashmap();
map.put(“成功”,true);
map.put(“数据”、“测试字符串”);
runBeanUtilsPopulate(地图);
runJacksonMapper(地图);
}
私有静态void runBeanUtilsPopulate(映射){
long t1=System.currentTimeMillis();
对于(int i=0;i
如果类中有泛型类型,则应将TypeReference
与convertValue()
一起使用
final ObjectMapper mapper=new ObjectMapper();
final MyPojo pojo=mapper.convertValue(映射,新类型引用(){});
您还可以使用它将pojo转换为java.util.Map
返回
final ObjectMapper mapper=new ObjectMapper();
final Map=mapper.convertValue(pojo,new-TypeReference(){});
将Map转换为POJO示例。请注意,Map键包含下划线,字段变量为驼峰
User.class POJO
import com.fasterxml.jackson.annotation.JsonProperty;
导入龙目数据;
@资料
公共类用户{
@JsonProperty(“用户名”)
私有字符串用户名;
@JsonProperty(“传递单词”)
私有字符串密码;
}
App.class将测试该示例
import java.util.HashMap;
导入java.util.Map;
导入com.fasterxml.jackson.databind.ObjectMapper;
公共类应用程序{
公共静态void main(字符串[]args){
Map info=newhashmap();
信息输入(“用户名”、“Q10Viking”);
信息输入(“传递单词”、“123456”);
ObjectMapper mapper=新的ObjectMapper();
User User=mapper.convertValue(info,User.class);
System.out.println(“------------------------------------”;
System.out.println(用户);
}
}
/**输出
-------------------------------
用户(用户名=Q10Viking,密码=123456)
*/
@Hamedz
如果使用多个数据,请使用Jackson进行转换
轻数据,使用apache。。。
测试用例:
导入java.lang.reflect.InvocationTargetException;
导入java.util.HashMap;
导入java.util.Map;
导入org.apache.commons.beanutils.beanutils;
导入com.fasterxml.jackson.databind.ObjectMapper;
导入lombok.allargsconstuctor;
导入龙目数据;
导入lombok.noargsconstuctor;
公共类TestPerf{
公共静态最终整数循环最大计数=1000;
公共静态void main(字符串[]args){
Map Map=newhashmap();
map.put(“成功”,true);
地图。放置(“数字”,1000);
地图放置(“更长”,1000L);
map.put(“倍增器”,1000D);
put(“data1”、“testString”);
put(“data2”、“testString”);
put(“data3”、“testString”);
put(“data4”、“testString”);
map.put(“data5”、“testString”);
map.put(“data6”、“testString”);
put(“data7”、“testString”);
map.put(“data8”、“testString”);
put(“data9”、“testString”);
map.put(“data10”、“testString”);
runBeanUtilsPopulate(地图);
runJacksonMapper(地图);
}
私有静态void runBeanUtilsPopulate(映射){
long t1=System.currentTimeMillis();
对于(int i=0;iGson gson = new Gson();
JsonElement jsonElement = gson.toJsonTree(map);
MyPojo pojo = gson.fromJson(jsonElement, MyPojo.class);
BeanUtils t2-t1 = 286
Jackson t2-t1 = 2203
public class MainMapToPOJO {
public static final int LOOP_MAX_COUNT = 1000;
public static void main(String[] args) {
Map<String, Object> map = new HashMap<>();
map.put("success", true);
map.put("data", "testString");
runBeanUtilsPopulate(map);
runJacksonMapper(map);
}
private static void runBeanUtilsPopulate(Map<String, Object> map) {
long t1 = System.currentTimeMillis();
for (int i = 0; i < LOOP_MAX_COUNT; i++) {
try {
TestClass bean = new TestClass();
BeanUtils.populate(bean, map);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
long t2 = System.currentTimeMillis();
System.out.println("BeanUtils t2-t1 = " + String.valueOf(t2 - t1));
}
private static void runJacksonMapper(Map<String, Object> map) {
long t1 = System.currentTimeMillis();
for (int i = 0; i < LOOP_MAX_COUNT; i++) {
ObjectMapper mapper = new ObjectMapper();
TestClass testClass = mapper.convertValue(map, TestClass.class);
}
long t2 = System.currentTimeMillis();
System.out.println("Jackson t2-t1 = " + String.valueOf(t2 - t1));
}}
import java.lang.reflect.InvocationTargetException;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.beanutils.BeanUtils;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
public class TestPerf {
public static final int LOOP_MAX_COUNT = 1000;
public static void main(String[] args) {
Map<String, Object> map = new HashMap<>();
map.put("success", true);
map.put("number", 1000);
map.put("longer", 1000L);
map.put("doubler", 1000D);
map.put("data1", "testString");
map.put("data2", "testString");
map.put("data3", "testString");
map.put("data4", "testString");
map.put("data5", "testString");
map.put("data6", "testString");
map.put("data7", "testString");
map.put("data8", "testString");
map.put("data9", "testString");
map.put("data10", "testString");
runBeanUtilsPopulate(map);
runJacksonMapper(map);
}
private static void runBeanUtilsPopulate(Map<String, Object> map) {
long t1 = System.currentTimeMillis();
for (int i = 0; i < LOOP_MAX_COUNT; i++) {
try {
TestClass bean = new TestClass();
BeanUtils.populate(bean, map);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
long t2 = System.currentTimeMillis();
System.out.println("BeanUtils t2-t1 = " + String.valueOf(t2 - t1));
}
private static void runJacksonMapper(Map<String, Object> map) {
long t1 = System.currentTimeMillis();
for (int i = 0; i < LOOP_MAX_COUNT; i++) {
ObjectMapper mapper = new ObjectMapper();
TestClass testClass = mapper.convertValue(map, TestClass.class);
}
long t2 = System.currentTimeMillis();
System.out.println("Jackson t2-t1 = " + String.valueOf(t2 - t1));
}
@Data
@AllArgsConstructor
@NoArgsConstructor
public static class TestClass {
private Boolean success;
private Integer number;
private Long longer;
private Double doubler;
private String data1;
private String data2;
private String data3;
private String data4;
private String data5;
private String data6;
private String data7;
private String data8;
private String data9;
private String data10;
}
}
public static <T> T convert(Map<String, Object> aMap, Class<T> t) {
try {
return objectMapper
.convertValue(aMap, objectMapper.getTypeFactory().constructType(t));
} catch (Exception e) {
log.error("converting failed! aMap: {}, class: {}", getJsonString(aMap), t.getClass().getSimpleName(), e);
}
return null;
}
ObjectMapper objectMapper = new ObjectMapper();
//if all properties are not in class use this
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
final MyPojo pojo = objectMapper.convertValue(map, MyPojo.class);