在某些情况下我们希望JSON按照一个比较友好的格式换行输出,不要都挤在一起,可以使用JACKSON实现。
- 引入Jackson
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.5</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.9.5</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>2.9.5</version>
</dependency>
- 格式化输出测试
public class JacksonTest {
@Test
public void test1() throws IOException {
ObjectMapper mapper = new ObjectMapper();
List list = new ArrayList<>();
Map map1 = new HashMap<>();
map1.put("id","111");
map1.put("users", Arrays.asList(1,2,3,4,5,5));
list.add(map1);
Map map2 = new HashMap();
map2.put("name","zqw");
list.add(map2);
//普通输出
System.out.println(mapper.writeValueAsString(list));
//格式化/美化/优雅的输出
System.out.println(mapper.writerWithDefaultPrettyPrinter().writeValueAsString(list));
String str = "[ {\n" +
" \"id\" : \"111\",\n" +
" \"users\" : [ 1, 2, 3, 4, 5, 5 ]\n" +
"}, {\n" +
" \"name\" : \"zqw\"\n" +
"} ]";
Object obj = mapper.readValue(str, Object.class);
System.out.println(mapper.writeValueAsString(obj));
System.out.println(mapper.writerWithDefaultPrettyPrinter().writeValueAsString(obj));
}
}