jackson_java与json转换

pom.xml

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.6.4</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.6.4</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-annotations</artifactId>
    <version>2.6.4</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.dataformat</groupId>
    <artifactId>jackson-dataformat-xml</artifactId>
    <version>2.6.4</version>
</dependency>

import

import java.io.ByteArrayOutputStream;
import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonEncoding;
import com.fasterxml.jackson.core.JsonGenerator;

java-->json

Map params = new HashMap();
params.put("userName", "maqingbin");
params.put("age", 12);
//
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
JsonFactory jsonF = new JsonFactory();
JsonGenerator jg = jsonF.createGenerator(byteArrayOutputStream, JsonEncoding.UTF8);
jg.useDefaultPrettyPrinter();
marshallingJson(jg,params);
String jsonStr=byteArrayOutputStream.toString();
//
//可以将这个方法改造一下变成通用
private void marshallingJson(JsonGenerator jg,Map params) throws IOException{
    jg.writeStartObject();
    jg.writeStringField("userName", params.get("userName").toString());
    jg.writeNumberField("age", (Integer)params.get("age"));
    jg.writeEndObject();
    jg.close();
}