json 和对象互相转换

json 和对象互相转换

导入 Jar 包：

import com.fasterxml.jackson.databind.ObjectMapper;

Maven 地址：

<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.9.8</version>
</dependency>

private static ObjectMapper objectMapper = new ObjectMapper();

把对象转换成 json 串

public static String toStr(Object obj) {
    String json_str = "";
    try {
        json_str = objectMapper.writer().writeValueAsString(obj);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return json_str;
}

把 json 串转换成对象

public static <T> T toObject(String jsonStr, Class<T> valueType) {
    try {
        return objectMapper.readValue(jsonStr, valueType);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

完整代码...

```java
import com.fasterxml.jackson.databind.ObjectMapper;

public class JsonUtil {

private static ObjectMapper objectMapper = new ObjectMapper();

public static String toStr(Object obj) {
    String json_str = "";
    try {
        json_str = objectMapper.writer().writeValueAsString(obj);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return json_str;
}

public static <T> T toObject(String jsonStr, Class<T> valueType) {
    try {
        return objectMapper.readValue(jsonStr, valueType);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

public static String createOperaStr(boolean b, String msg) {
    return "{\"success\":" + b + ",\"msgText\":\"" + msg + "\"}";
}

}

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