pom.xml需要增加如下依赖：
<dependency> <groupId>org.codehaus.jackson</groupId> <artifactId>jackson-core-lgpl</artifactId> <version>1.9.1</version> </dependency> <dependency> <groupId>org.codehaus.jackson</groupId> <artifactId>jackson-mapper-lgpl</artifactId> <version>1.9.1</version> </dependency>
package com.zuidaima.json;
import java.io.File;
import java.io.IOException;
import org.codehaus.jackson.JsonEncoding;
import org.codehaus.jackson.JsonFactory;
import org.codehaus.jackson.JsonGenerationException;
import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.JsonParser;
import org.codehaus.jackson.JsonToken;
import org.codehaus.jackson.map.JsonMappingException;
public class JsonGeneratorAndParser {
/**
* @param args
*/
public static void main(String[] args) {
try {
JsonFactory jfactory = new JsonFactory();
/*** write to file ***/
JsonGenerator jGenerator = jfactory.createJsonGenerator(new File(
"c:/user.json"), JsonEncoding.UTF8);
jGenerator.writeStartObject(); // {
jGenerator.writeStringField("name", "java牛"); // "name" : "java牛"
jGenerator.writeNumberField("age", 29); // "age" : 29
jGenerator.writeFieldName("messages"); // "messages" :
jGenerator.writeStartArray(); // [
jGenerator.writeString("msg 1"); // "msg 1"
jGenerator.writeString("msg 2"); // "msg 2"
jGenerator.writeString("msg 3"); // "msg 3"
jGenerator.writeEndArray(); // ]
jGenerator.writeEndObject(); // }
jGenerator.close();
JsonParser jParser = jfactory.createJsonParser(new File(
"c:/user.json"));
// loop until token equal to "}"
while (jParser.nextToken() != JsonToken.END_OBJECT) {
String fieldname = jParser.getCurrentName();
if ("name".equals(fieldname)) {
// current token is "name",
// move to next, which is "name"‘s value
jParser.nextToken();
System.out.println(jParser.getText());
}
if ("age".equals(fieldname)) {
// current token is "age",
// move to next, which is "name"‘s value
jParser.nextToken();
System.out.println(jParser.getIntValue()); // display 29
}
if ("messages".equals(fieldname)) {
jParser.nextToken(); // current token is "[", move next
// messages is array, loop until token equal to "]"
while (jParser.nextToken() != JsonToken.END_ARRAY) {
// display msg1, msg2, msg3
System.out.println(jParser.getText());
}
}
}
jParser.close();
} catch (JsonGenerationException e) {
e.printStackTrace();
} catch (JsonMappingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
转载请标明出处:通过codehaus来实现json写入文件和读取文件成json对象