Spring MVC 整合 JSON 视图
Jackson转换Java对象
1、 jackson有专门的视图MappingJacksonJsonView，只需用配置这个视图就可以完成转换json了。使用jackson需要添加如下jar包：
如果你对Jackson转换Java对象还没有什么了解的话，你可以参考：
For cnblogs：http://www.cnblogs.com/hoojo/archive/2011/04/22/2024628.html
For csdn：http://blog.csdn.net/IBM_hoojo/archive/2011/04/22/6340762.aspx
2、 然后需要在dispatcher.xml中添加视图配置，配置如下：
<bean name="jsonView" class="org.springframework.web.servlet.view.json.MappingJacksonJsonView">
<property name="encoding">
<value type="org.codehaus.jackson.JsonEncoding">UTF8value>
property>
<property name="contentType" value="text/html;charset=UTF-8"/>
bean>
3、 将Java对象转换JSON
package com.hoo.controller;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import com.hoo.entity.Account;
import com.hoo.entity.Brithday;
import com.hoo.entity.User;
/**
* function:用MappingJacksonJsonView视图和Jackson转换Json
* @author hoojo
* @createDate 2011-4-28 下午04:52:23
* @file JacksonJsonViewController.java
* @package com.hoo.controller
* @project SpringMVC4View
* @blog http://blog.csdn.net/IBM_hoojo
* @email [email protected]
* @version 1.0
*/
@Controller
@RequestMapping("/jackson/view")
public class JacksonJsonViewController {
/**
* function:转换普通Java对象
* @author hoojo
* @createDate 2011-4-28 下午05:14:18
* @return
*/
@RequestMapping("/doBeanJsonView")
public ModelAndView doBeanJsonView() {
System.out.println("#################ViewController doBeanJsonView##################");
ModelAndView mav = new ModelAndView("jsonView");
User user = new User();
user.setAddress("china GuangZhou");
user.setAge(23);
user.setBrithday(new Date());
user.setName("jack");
user.setSex(true);
Account bean = new Account();
bean.setAddress("北京");
bean.setEmail("email");
bean.setId(1);
bean.setName("haha");
Brithday day = new Brithday();
day.setBrithday("2010-11-22");
bean.setBrithday(day);
mav.addObject(bean);
return mav;
}
}
上面使用了刚才我们配置的jsonView视图，通过这个视图就可以将ModelAndView中的数据转换成JSON数据。
在浏览器中请求：http://localhost:8080/SpringMVC4View/jackson/view/doBeanJsonView.do
结果如下：
{"account":{"address":"北京","name":"haha","id":1,"email":"email","brithday":{"brithday":"2010-11-22"}}}
4、 转换Map到JSON
/**
* function:转换Map集合
* @author hoojo
* @createDate 2011-4-28 下午05:14:33
* @return
*/
@RequestMapping("/doMapJsonView")
public ModelAndView doMapJsonView() {
System.out.println("#################ViewController doBeanJsonView##################");
ModelAndView mav = new ModelAndView("jsonView");
User user = new User();
user.setAddress("china GuangZhou");
user.setAge(23);
user.setBrithday(new Date());
user.setName("jack");
user.setSex(true);
Map
map.put("user", user);
map.put("success", true);
mav.addObject(map);
mav.addObject("title", "ViewController doBeanJsonView");
return mav;
}
在WebBrowser中请求：http://localhost:8080/SpringMVC4View/jackson/view/doMapJsonView.do
结果如下：
{"hashMap":{"success":true,"user":{"address":"china GuangZhou","name":"jack","age":23,"sex":true,"brithday":1303982296953}},
"title":"ViewController doBeanJsonView"}
5、 转换List到JSON
/**
* function:转换List集合
* @author hoojo
* @createDate 2011-4-28 下午05:14:54
* @return
*/
@RequestMapping("/doListJsonView")
public ModelAndView doListJsonView() {
System.out.println("#################ViewController doBeanJsonView##################");
ModelAndView mav = new ModelAndView("jsonView");
List<User> list = new ArrayList<User>();
for (int i = 0; i < 3; i++) {
User user = new User();
user.setAddress("china GuangZhou#" + i);
user.setAge(23 + i);
user.setBrithday(new Date());
user.setName("jack_" + i);
user.setSex(true);
list.add(user);
}
mav.addObject(list);
return mav;
}
在浏览器中请求http://localhost:8080/SpringMVC4View/jackson/view/doListJsonView.do
结果如下：
{"userList":[{"address":"china GuangZhou#0","name":"jack_0","age":23,"sex":true,"brithday":1303982399265},
{"address":"china GuangZhou#1","name":"jack_1","age":24,"sex":true,"brithday":1303982399265},
{"address":"china GuangZhou#2","name":"jack_2","age":25,"sex":true,"brithday":1303982399265}]}
总结，spring对jackson提供了专门的视图，整合起来也比较方便。而且jackson也比较简单易用。
七、 JSON-lib转换Java到JSON
1、 Spring没有提供JSON-lib的view视图，不过没有关系。我们可以自己扩展一个，只需用继承AbstractView类，实现里面的方法就可以了。首先你需要了解JSON-lib，如果你还不了解JSON-lib的话，建议阅读：
For cnblogs: http://www.cnblogs.com/hoojo/archive/2011/04/21/2023805.html
For csdn: http://blog.csdn.net/IBM_hoojo/archive/2011/04/21/6339246.aspx
然后你需要在工程中添加如下jar文件：
2、 因为Spring没有提供view，我们需要自己实现一个。代码如下：
package com.hoo.veiw.xml;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import net.sf.json.JSONSerializer;
import net.sf.json.JsonConfig;
import org.springframework.util.CollectionUtils;
import org.springframework.validation.BindingResult;
import org.springframework.web.servlet.view.AbstractView;
/**
* function:扩展AbstractView 实现JSON-lib视图
* @author hoojo
* @createDate 2011-4-28 下午05:26:43
* @file MappingJsonlibVeiw.java
* @package com.hoo.veiw.xml
* @project SpringMVC4View
* @blog http://blog.csdn.net/IBM_hoojo
* @email [email protected]
* @version 1.0
*/
public class MappingJsonlibVeiw extends AbstractView {
public static final String DEFAULT_CONTENT_TYPE = "application/json";
public static final String DEFAULT_CHAR_ENCODING = "UTF-8";
private String encodeing = DEFAULT_CHAR_ENCODING;
public void setEncodeing(String encodeing) {
this.encodeing = encodeing;
}
private Set renderedAttributes;
private JsonConfig cfg = null;
public void setCfg(JsonConfig cfg) {
this.cfg = cfg;
}
public MappingJsonlibVeiw() {
setContentType(DEFAULT_CONTENT_TYPE);
}
@Override
protected void renderMergedOutputModel(Map
HttpServletResponse response) throws Exception {
model = filterModel(model);
response.setCharacterEncoding(encodeing);
PrintWriter out = response.getWriter();
if (cfg == null) {
out.print(JSONSerializer.toJSON(model));
} else {
out.print(JSONSerializer.toJSON(model, cfg));
}
}
/**
* Filters out undesired attributes from the given model.
* Default implementation removes {@link BindingResult} instances and entries not included in the {@link
* #setRenderedAttributes(Set) renderedAttributes} property.
*/
protected Map
Map
Set renderedAttributes =
!CollectionUtils.isEmpty(this.renderedAttributes) ? this.renderedAttributes : model.keySet();
for (Map.Entry
if (!(entry.getValue() instanceof BindingResult) && renderedAttributes.contains(entry.getKey())) {
result.put(entry.getKey(), entry.getValue());
}
}
return result;
}
}
上面的代码不是很复杂，首先我们设置contentType，这个属性在AbstractView这个父类中有setter方法可以完成设置。
然后就是默认的编码格式，这个编码格式设置到response上。默认UTF-8编码。在renderMergedOutputModel方法中可以看到设置。
第三就是filterModule方法，这个方法是得到ModelAndView中我们添加对象，过滤掉BindingResult的信息。
最后就是renderMergedOutputModel方法，这个方法最为核心，但也很简单。过滤model获得要转换的model数据，设置response编码格式。利用response的Writer输出JSON信息，通过JSONSerializer转换Java到JSON。
3、 在dispatcher.xml中配置jsonlibView这个视图
<-- 自定义JSONlib的json视图 -->
<bean name="jsonlibView" class="com.hoo.veiw.xml.MappingJsonlibVeiw">
<property name="contentType" value="text/html;charset=UTF-8"/>
<property name="encodeing" value="gbk"/>
bean>
4、 转换普通Java对象
package com.hoo.controller;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import com.hoo.entity.Account;
import com.hoo.entity.Brithday;
import com.hoo.entity.User;
/**
* function:
* @author hoojo
* @createDate 2011-4-28 下午05:58:02
* @file JsonlibMappingViewController.java
* @package com.hoo.controller
* @project SpringMVC4View
* @blog http://blog.csdn.net/IBM_hoojo
* @email [email protected]
* @version 1.0
*/
@Controller
@RequestMapping("/jsonlib/view")
public class JsonlibMappingViewController {
/**
* function:转换普通Java对象
* @author hoojo
* @createDate 2011-4-28 下午05:14:18
* @return
*/
@RequestMapping("/doBeanJsonView")
public ModelAndView doBeanJsonView() {
System.out.println("#################ViewController doBeanJsonView##################");
ModelAndView mav = new ModelAndView("jsonlibView");
User user = new User();
user.setAddress("china GuangZhou");
user.setAge(23);
user.setBrithday(new Date());
user.setName("jack");
user.setSex(true);
Account bean = new Account();
bean.setAddress("北京");
bean.setEmail("email");
bean.setId(1);
bean.setName("haha");
Brithday day = new Brithday();
day.setBrithday("2010-11-22");
bean.setBrithday(day);
mav.addObject(bean);
return mav;
}
}
在WebBrowser中请求http://localhost:8080/SpringMVC4View/jsonlib/view/doBeanJsonView.do
结果如下：
{"account":{"address":"北京","brithday":{"brithday":"2010-11-22"},"email":"email","id":1,"name":"haha"}}
5、 转换Map到JSON
/**
* function:转换Map集合
* @author hoojo
* @createDate 2011-4-28 下午05:14:33
* @return
*/
@RequestMapping("/doMapJsonView")
public ModelAndView doMapJsonView() {
System.out.println("#################ViewController doBeanJsonView##################");
ModelAndView mav = new ModelAndView("jsonlibView");
User user = new User();
user.setAddress("china GuangZhou");
user.setAge(23);
user.setBrithday(new Date());
user.setName("jack");
user.setSex(true);
Map
map.put("user", user);
map.put("success", true);
mav.addObject(map);
mav.addObject("title", "ViewController doBeanJsonView");
return mav;
}
在WebBrowser中请求http://localhost:8080/SpringMVC4View/jsonlib/view/doMapJsonView.do
结果如下：
{"hashMap":{"success":true,"user":{"address":"china GuangZhou","age":23,
"brithday":{"date":28,"day":4,"hours":18,"minutes":20,"month":3,"seconds":8,
"time":1303986008703,"timezoneOffset":-480,"year":111},"name":"jack","sex":true}},
"title":"ViewController doBeanJsonView"}
发现时间被分解成一个对象了，这里需要用JSONConfig的JsonValueProcessor将brithday过滤下，然后用SimpleDateFormate进行格式转换。
6、 转换List集合
/**
* function:转换List集合
* @author hoojo
* @createDate 2011-4-28 下午05:14:54
* @return
*/
@RequestMapping("/doListJsonView")
public ModelAndView doListJsonView() {
System.out.println("#################ViewController doBeanJsonView##################");
ModelAndView mav = new ModelAndView("jsonlibView");
List<User> list = new ArrayList<User>();
for (int i = 0; i < 3; i++) {
User user = new User();
user.setAddress("china GuangZhou#" + i);
user.setAge(23 + i);
user.setBrithday(new Date());
user.setName("jack_" + i);
user.setSex(true);
list.add(user);
}
mav.addObject(list);
return mav;
}
在浏览器中请求http://localhost:8080/SpringMVC4View/jsonlib/view/doListJsonView.do
结果如下：
{"userList":[{"address":"china GuangZhou#0","age":23,"brithday":{"date":28,"day":4,"hours":19,"minutes":2,"month":3,"seconds":54,
"time":1303988574328,"timezoneOffset":-480,"year":111},"name":"jack_0","sex":true},
{"address":"china GuangZhou#1","age":24,"brithday":{"date":28,"day":4,"hours":19,"minutes":2,"month":3,"seconds":54,
"time":1303988574328,"timezoneOffset":-480,"year":111},"name":"jack_1","sex":true},{"address":"china GuangZhou#2","age":25,
"brithday":{"date":28,"day":4,"hours":19,"minutes":2,"month":3,"seconds":54,"time":1303988574328,"timezoneOffset":-480,"year":111},
"name":"jack_2","sex":true}]}