package com.e6.ztest; import java.util.Date; import org.codehaus.jackson.map.annotate.JsonSerialize; public class Birthday { private Date dateBirth; private String birthdayTx; public String getBirthdayTx() { return birthdayTx; } public void setBirthdayTx(String birthdayTx) { this.birthdayTx = birthdayTx; } @JsonSerialize(using = JsonDateSerializer.class) public Date getDateBirth() { return dateBirth; } public void setDateBirth(Date dateBirth) { this.dateBirth = dateBirth; } public Birthday() { } }
package com.e6.ztest; public class AccountBean { private int id; private String name; private String email; private String address; private Birthday birthday; //getter、setter @Override public String toString() { return this.name + "#" + this.id + "#" + this.address + "#" + this.birthday + "#" + this.email; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } public Birthday getBirthday() { return birthday; } public void setBirthday(Birthday birthday) { this.birthday = birthday; } }
package com.e6.ztest; import java.io.IOException; import java.text.SimpleDateFormat; import java.util.Date; import org.codehaus.jackson.JsonGenerator; import org.codehaus.jackson.JsonProcessingException; import org.codehaus.jackson.map.JsonSerializer; import org.codehaus.jackson.map.SerializerProvider; public class JsonDateSerializer extends JsonSerializer<Date> { @Override public void serialize(Date arg0, JsonGenerator arg1, SerializerProvider arg2) throws IOException, JsonProcessingException {
//"yyyy-MM-dd'T'HH:mm:ss.SSSZ"
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
String formattedDate = formatter.format(arg0);
arg1.writeString(formattedDate);
}
}
package com.e6.ztest; import java.io.IOException; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.Iterator; import java.util.LinkedHashMap; import java.util.List; import java.util.Map; import java.util.Set; import org.codehaus.jackson.JsonEncoding; import org.codehaus.jackson.JsonGenerator; import org.codehaus.jackson.JsonParseException; import org.codehaus.jackson.map.JsonMappingException; import org.codehaus.jackson.map.ObjectMapper; import org.codehaus.jackson.node.JsonNodeFactory; import org.junit.After; import org.junit.Before; import org.junit.Test; public class JsonTest { private JsonGenerator jsonGenerator = null; private ObjectMapper objectMapper = null; private AccountBean bean = null; @Before public void init() { bean = new AccountBean(); bean.setAddress("china-Guangzhou"); bean.setEmail("[email protected]"); bean.setId(1); bean.setName("hoojo"); objectMapper = new ObjectMapper(); try { jsonGenerator = objectMapper.getJsonFactory().createJsonGenerator( System.out, JsonEncoding.UTF8); } catch (IOException e) { e.printStackTrace(); } } @After public void destory() { try { if (jsonGenerator != null) { jsonGenerator.flush(); } if (!jsonGenerator.isClosed()) { jsonGenerator.close(); } jsonGenerator = null; objectMapper = null; bean = null; System.gc(); } catch (IOException e) { e.printStackTrace(); } } @Test public void writeEntityJSON() { try { System.out.println("jsonGenerator"); // writeObject可以转换java对象,eg:JavaBean/Map/List/Array等 jsonGenerator.writeObject(bean); System.out.println(); System.out.println("ObjectMapper"); // writeValue具有和writeObject相同的功能 objectMapper.writeValue(System.out, bean); } catch (IOException e) { e.printStackTrace(); } } // // 上面分别利用JsonGenerator的writeObject方法和ObjectMapper的writeValue方法完成对Java对象的转换,二者传递的参数及构造的方式不同;JsonGenerator的创建依赖于ObjectMapper对象。也就是说如果你要使用JsonGenerator来转换JSON,那么你必须创建一个ObjectMapper。但是你用ObjectMapper来转换JSON,则不需要JSONGenerator。 // // objectMapper的writeValue方法可以将一个Java对象转换成JSON。这个方法的参数一,需要提供一个输出流,转换后可以通过这个流来输出转换后的内容。或是提供一个File,将转换后的内容写入到File中。当然,这个参数也可以接收一个JSONGenerator,然后通过JSONGenerator来输出转换后的信息。第二个参数是将要被转换的Java对象。如果用三个参数的方法,那么是一个Config。这个config可以提供一些转换时的规则,过指定的Java对象的某些属性进行过滤或转换等。 // // 2、 将Map集合转换成Json字符串 /** * <b>function:</b>将map转换成json字符串 * @author hoojo * @createDate 2010-11-23 下午06:05:26 */ @Test public void writeMapJSON() { try { Map<String, Object> map = new HashMap<String, Object>(); map.put("name", bean.getName()); map.put("account", bean); bean = new AccountBean(); bean.setAddress("china-Beijin"); bean.setEmail("[email protected]"); Birthday bir = new Birthday(); bir.setBirthdayTx("1988/01/30"); bir.setDateBirth(new Date()); bean.setBirthday(bir); map.put("account2", bean); System.out.println("jsonGenerator"); jsonGenerator.writeObject(map); System.out.println(""); System.out.println("objectMapper"); objectMapper.writeValue(System.out, map); } catch (IOException e) { e.printStackTrace(); } } // 转换后结果如下: //jsonGenerator // {"account2":{"id":0,"name":null,"email":"[email protected]","address":"china-Beijin","birthday":{"dateBirth":"2014-03-25T00:33:09.709+0800","birthdayTx":"1988/01/30"}},"name":"hoojo","account":{"id":1,"name":"hoojo","email":"[email protected]","address":"china-Guangzhou","birthday":null}} // objectMapper // {"account2":{"id":0,"name":null,"email":"[email protected]","address":"china-Beijin","birthday":{"dateBirth":"2014-03-25T00:33:09.709+0800","birthdayTx":"1988/01/30"}},"name":"hoojo","account":{"id":1,"name":"hoojo","email":"[email protected]","address":"china-Guangzhou","birthday":null}} // 3、 将List集合转换成json /** * <b>function:</b>将list集合转换成json字符串 * @author hoojo * @createDate 2010-11-23 下午06:05:59 */ @Test public void writeListJSON() { try { List<AccountBean> list = new ArrayList<AccountBean>(); list.add(bean); bean = new AccountBean(); bean.setId(2); bean.setAddress("address2"); bean.setEmail("email2"); bean.setName("haha2"); list.add(bean); System.out.println("jsonGenerator"); //list转换成JSON字符串 jsonGenerator.writeObject(list); System.out.println(); System.out.println("ObjectMapper"); //用objectMapper直接返回list转换成的JSON字符串 System.out.println("1###" + objectMapper.writeValueAsString(list)); System.out.print("2###"); //objectMapper list转换成JSON字符串 objectMapper.writeValue(System.out, list); } catch (IOException e) { e.printStackTrace(); } } // 结果如下: // // jsonGenerator // [{"address":"china-Guangzhou","name":"hoojo","id":1,"birthday":null,"email":"[email protected]"}, // {"address":"address2","name":"haha2","id":2,"birthday":null,"email":"email2"}] // ObjectMapper // 1###[{"address":"china-Guangzhou","name":"hoojo","id":1,"birthday":null,"email":"[email protected]"}, // {"address":"address2","name":"haha2","id":2,"birthday":null,"email":"email2"}] // 2###[{"address":"china-Guangzhou","name":"hoojo","id":1,"birthday":null,"email":"[email protected]"}, // {"address":"address2","name":"haha2","id":2,"birthday":null,"email":"email2"}] // 外面就是多了个[]中括号;同样Array也可以转换,转换的JSON和上面的结果是一样的,这里就不再转换了。~.~ // // 4、下面来看看jackson提供的一些类型,用这些类型完成json转换;如果你使用这些类型转换JSON的话,那么你即使没有JavaBean(Entity)也可以完成复杂的Java类型的JSON转换。下面用到这些类型构建一个复杂的Java对象,并完成JSON转换。 @Test public void writeOthersJSON() { try { String[] arr = { "a", "b", "c" }; System.out.println("jsonGenerator"); String str = "hello world jackson!"; //byte jsonGenerator.writeBinary(str.getBytes()); //boolean jsonGenerator.writeBoolean(true); //null jsonGenerator.writeNull(); //float jsonGenerator.writeNumber(2.2f); //char jsonGenerator.writeRaw("c"); //String jsonGenerator.writeRaw(str, 5, 10); //String jsonGenerator.writeRawValue(str, 5, 5); //String jsonGenerator.writeString(str); jsonGenerator.writeTree(JsonNodeFactory.instance.POJONode(str)); System.out.println(); //Object jsonGenerator.writeStartObject();//{ jsonGenerator.writeObjectFieldStart("user");//user:{ jsonGenerator.writeStringField("name", "jackson");//name:jackson jsonGenerator.writeBooleanField("sex", true);//sex:true jsonGenerator.writeNumberField("age", 22);//age:22 jsonGenerator.writeEndObject();//} jsonGenerator.writeArrayFieldStart("infos");//infos:[ jsonGenerator.writeNumber(22);//22 jsonGenerator.writeString("this is array");//this is array jsonGenerator.writeEndArray();//] jsonGenerator.writeEndObject();//} AccountBean bean = new AccountBean(); bean.setAddress("address"); bean.setEmail("email"); bean.setId(1); bean.setName("haha"); //complex Object jsonGenerator.writeStartObject();//{ jsonGenerator.writeObjectField("user", bean);//user:{bean} jsonGenerator.writeObjectField("infos", arr);//infos:[array] jsonGenerator.writeEndObject();//} } catch (Exception e) { e.printStackTrace(); } } // 运行后,结果如下: // // jsonGenerator // "aGVsbG8gd29ybGQgamFja3NvbiE=" true null 2.2c world jac worl "hello world jackson!" "hello world jackson!" // {"user":{"name":"jackson","sex":true,"age":22},"infos":[22,"this is array"]} // {"user":{"address":"address","name":"haha","id":1,"birthday":null,"email":"email"},"infos":["a","b","c"]} // 怎么样?构造的json字符串和输出的结果是一致的吧。关键看懂用JSONGenerator提供的方法,完成一个Object的构建。 // // 三、JSON转换成Java对象 // // 1、 将json字符串转换成JavaBean对象 @Test public void readJson2Entity() { String json = "{\"address\":\"address\",\"name\":\"haha\",\"id\":1,\"email\":\"email\",\"birthday\":{\"birthdayTx\":\"1988/01/30\",\"dateBirth\":\"2014-03-24\"}}"; try { AccountBean acc = objectMapper.readValue(json, AccountBean.class); System.out.println(acc.getName()); System.out.println(acc.getBirthday().getDateBirth().toString()); } catch (JsonParseException e) { e.printStackTrace(); } catch (JsonMappingException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } // 很简单,用到了ObjectMapper这个对象的readValue这个方法,这个方法需要提供2个参数。第一个参数就是解析的JSON字符串,第二个参数是即将将这个JSON解析成什么Java对象,Java对象的类型。 //当然,还有其他相同签名方法,如果你有兴趣可以一一尝试使用方法, //当然使用的方法和当前使用的方法大同小异。运行后,结果如下: // // haha // Mon Mar 24 08:00:00 CST 2014 // 2、 将json字符串转换成List<Map>集合 /** * <b>function:</b>json字符串转换成list<map> * @author hoojo * @createDate 2010-11-23 下午06:12:01 */ @Test public void readJson2List() { String json = "[{\"address\": \"address2\",\"name\":\"haha2\",\"id\":2,\"email\":\"email2\"},"+ "{\"address\":\"address\",\"name\":\"haha\",\"id\":1,\"email\":\"email\"}]"; try { List<LinkedHashMap<String, Object>> list = objectMapper.readValue(json, List.class); System.out.println(list.size()); for (int i = 0; i < list.size(); i++) { Map<String, Object> map = list.get(i); Set<String> set = map.keySet(); for (Iterator<String> it = set.iterator();it.hasNext();) { String key = it.next(); System.out.println(key + ":" + map.get(key)); } } } catch (JsonParseException e) { e.printStackTrace(); } catch (JsonMappingException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } // 尝试过将上面的JSON转换成List,然后List中存放AccountBean,但结果失败了。但是支持Map集合。因为你转成List.class,但是不知道List存放何种类型。只好默然Map类型。因为所有的对象都可以转换成Map结合,运行后结果如下: // // 2 // address:address2 // name:haha2 // id:2 // email:email2 // address:address // name:haha // id:1 // email:email // 3、 Json字符串转换成Array数组,由于上面的泛型转换不能识别到集合中的对象类型。所有这里用对象数组,可以解决这个问题。只不过它不再是集合,而是一个数组。当然这个不重要,你可以用Arrays.asList将其转换成List即可。 /** * <b>function:</b>json字符串转换成Array * @author hoojo * @createDate 2010-11-23 下午06:14:01 */ @Test public void readJson2Array() { String json = "[{\"address\": \"address2\",\"name\":\"haha2\",\"id\":2,\"email\":\"email2\"},"+ "{\"address\":\"address\",\"name\":\"haha\",\"id\":1,\"email\":\"email\"}]"; try { AccountBean[] arr = objectMapper.readValue(json, AccountBean[].class); System.out.println(arr.length); for (int i = 0; i < arr.length; i++) { System.out.println(arr[i]); } } catch (JsonParseException e) { e.printStackTrace(); } catch (JsonMappingException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } // 运行后的结果: // // 2 // haha2#2#address2#null#email2 // haha#1#address#null#email // 4、 Json字符串转换成Map集合 /** * <b>function:</b>json字符串转换Map集合 * @author hoojo * @createDate Nov 27, 2010 3:00:06 PM */ @Test public void readJson2Map() { String json = "{\"success\":true,\"A\":{\"address\": \"address2\",\"name\":\"haha2\",\"id\":2,\"email\":\"email2\"},"+ "\"B\":{\"address\":\"address\",\"name\":\"haha\",\"id\":1,\"email\":\"email\"}}"; try { Map<String, Map<String, Object>> maps = objectMapper.readValue(json, Map.class); System.out.println(maps.size()); Set<String> key = maps.keySet(); Iterator<String> iter = key.iterator(); while (iter.hasNext()) { String field = iter.next(); System.out.println(field + ":" + maps.get(field)); } } catch (JsonParseException e) { e.printStackTrace(); } catch (JsonMappingException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } // 运行后结果如下: // 3 // success:true // A:{address=address2, name=haha2, id=2, email=email2} // B:{address=address, name=haha, id=1, email=email} // 四、Jackson对XML的支持 // // Jackson也可以完成java对象到xml的转换,转换后的结果要比json-lib更直观,不过它依赖于stax2-api.jar这个jar包。 /** * <b>function:</b>java对象转换成xml文档 * 需要额外的jar包 stax2-api.jar * @author hoojo * @createDate 2010-11-23 下午06:11:21 */ // @Test // public void writeObject2Xml() { // //stax2-api-3.0.2.jar // System.out.println("XmlMapper"); // XmlMapper xml = new XmlMapper(); // // try { // //javaBean转换成xml // //xml.writeValue(System.out, bean); // StringWriter sw = new StringWriter(); // xml.writeValue(sw, bean); // System.out.println(sw.toString()); // //List转换成xml // List<AccountBean> list = new ArrayList<AccountBean>(); // list.add(bean); // list.add(bean); // System.out.println(xml.writeValueAsString(list)); // // //Map转换xml文档 // Map<String, AccountBean> map = new HashMap<String, AccountBean>(); // map.put("A", bean); // map.put("B", bean); // System.out.println(xml.writeValueAsString(map)); // } catch (JsonGenerationException e) { // e.printStackTrace(); // } catch (JsonMappingException e) { // e.printStackTrace(); // } catch (IOException e) { // e.printStackTrace(); // } // } // 运行上面的方法,结果如下: // // XmlMapper // <unknown><address>china-Guangzhou</address><name>hoojo</name><id>1</id><birthday/><email>[email protected]</email></unknown> // <unknown><unknown><address>china-Guangzhou</address><name>hoojo</name><id>1</id><birthday/><email>[email protected]</email></unknown> // <email><address>china-Guangzhou</address><name>hoojo</name><id>1</id><birthday/><email>[email protected]</email></email></unknown> // <unknown><A><address>china-Guangzhou</address><name>hoojo</name><id>1</id><birthday/><email>[email protected]</email></A> // <B><address>china-Guangzhou</address><name>hoojo</name><id>1</id><birthday/><email>[email protected]</email></B></unknown> // 看结果,根节点都是unknown 这个问题还没有解决,由于根节点没有转换出来,所有导致解析xml到Java对象,也无法完成。 }
只支持以上几种格式否则报错
Letter |
Date or Time Component |
Presentation |
Examples |
G |
Era designator |
AD |
|
y |
Year |
1996;96 |
|
M |
Month in year |
July;Jul;07 |
|
w |
Week in year |
27 |
|
W |
Week in month |
2 |
|
D |
Day in year |
189 |
|
d |
Day in month |
10 |
|
F |
Day of week in month |
2 |
|
E |
Day in week |
Tuesday;Tue |
|
a |
Am/pm marker |
PM |
|
H |
Hour in day (0-23) |
0 |
|
k |
Hour in day (1-24) |
24 |
|
K |
Hour in am/pm (0-11) |
0 |
|
h |
Hour in am/pm (1-12) |
12 |
|
m |
Minute in hour |
30 |
|
s |
Second in minute |
55 |
|
S |
Millisecond |
978 |
|
z |
Time zone |
Pacific Standard Time;PST;GMT-08:00 |
|
Z |
Time zone |
-0800 |
Date and Time Pattern |
Result |
"yyyy.MM.dd G 'at' HH:mm:ss z" |
2001.07.04 AD at 12:08:56 PDT |
"EEE, MMM d, ''yy" |
Wed, Jul 4, '01 |
"h:mm a" |
12:08 PM |
"hh 'o''clock' a, zzzz" |
12 o'clock PM, Pacific Daylight Time |
"K:mm a, z" |
0:08 PM, PDT |
"yyyyy.MMMMM.dd GGG hh:mm aaa" |
02001.July.04 AD 12:08 PM |
"EEE, d MMM yyyy HH:mm:ss Z" |
Wed, 4 Jul 2001 12:08:56 -0700 |
"yyMMddHHmmssZ" |
010704120856-0700 |
"yyyy-MM-dd'T'HH:mm:ss.SSSZ" |
2001-07-04T12:08:56.235-0700 |
"yyyy-MM-dd'T'HH:mm:ss.SSSXXX" |
2001-07-04T12:08:56.235-07:00 |
"YYYY-'W'ww-u" |
2001-W27-3 |
只支持以上几种格式否则报错
Letter |
Date or Time Component |
Presentation |
Examples |
G |
Era designator |
AD |
|
y |
Year |
1996;96 |
|
M |
Month in year |
July;Jul;07 |
|
w |
Week in year |
27 |
|
W |
Week in month |
2 |
|
D |
Day in year |
189 |
|
d |
Day in month |
10 |
|
F |
Day of week in month |
2 |
|
E |
Day in week |
Tuesday;Tue |
|
a |
Am/pm marker |
PM |
|
H |
Hour in day (0-23) |
0 |
|
k |
Hour in day (1-24) |
24 |
|
K |
Hour in am/pm (0-11) |
0 |
|
h |
Hour in am/pm (1-12) |
12 |
|
m |
Minute in hour |
30 |
|
s |
Second in minute |
55 |
|
S |
Millisecond |
978 |
|
z |
Time zone |
Pacific Standard Time;PST;GMT-08:00 |
|
Z |
Time zone |
-0800 |
Date and Time Pattern |
Result |
"yyyy.MM.dd G 'at' HH:mm:ss z" |
2001.07.04 AD at 12:08:56 PDT |
"EEE, MMM d, ''yy" |
Wed, Jul 4, '01 |
"h:mm a" |
12:08 PM |
"hh 'o''clock' a, zzzz" |
12 o'clock PM, Pacific Daylight Time |
"K:mm a, z" |
0:08 PM, PDT |
"yyyyy.MMMMM.dd GGG hh:mm aaa" |
02001.July.04 AD 12:08 PM |
"EEE, d MMM yyyy HH:mm:ss Z" |
Wed, 4 Jul 2001 12:08:56 -0700 |
"yyMMddHHmmssZ" |
010704120856-0700 |
"yyyy-MM-dd'T'HH:mm:ss.SSSZ" |
2001-07-04T12:08:56.235-0700 |
"yyyy-MM-dd'T'HH:mm:ss.SSSXXX" |
2001-07-04T12:08:56.235-07:00 |
"YYYY-'W'ww-u" |
2001-W27-3 |