使用Spring MVC 4构建RESTful服务相对于其它框架来说,有很多优势。首先,Spring MVC 4作为Spring的框架之一,可以很好地与Spring进行集成。其次,Spring MVC 4的拦截器是在方法层级上的拦截,相对于其它MVC框架(如Struts2)的拦截器具有更高的效率。再者,Spring MVC 4采用基于注解的配置,入手容易,开发灵活。
Spring MVC 4采用的是jacson解析JSON。jacson一款非常高效强大的JSON工具类,可以轻松地在JAVA对象与json对象和XML文档之间进行序列化和反序列化。本文中的例子采用的是Spring 4.1.1.RELEASE和jacson 2.4.0版本,经测试无任何异常。接下来,上干货:
开发环境准备:
Eclipse Luna
Apache Tomcat 8.0
JDK 1.7
Spring 4.1.1.RELEASE
jackson 2.4.0
工程目录如下:
1. 新建Maven Project,选择在“Archetype类型”中,选择“maven-archetype-webapp”。
2. 在Pom.xml中添加 Maven 依赖,从而可以使用 Spring和jackson中的特性。如果读者使用的是Dynamic Web Project,可以从Maven仓库下载对的Spring Jar和 jacson jar。
Spring的Maven仓库地址:http://repo1.maven.org/maven2/org/springframework/
jackson的Maven仓库地址:http://repo1.maven.org/maven2/com/fasterxml/jackson/core/
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<
project
xmlns
=
"http://maven.apache.org/POM/4.0.0"
xmlns:xsi
=
"http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation
=
"http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"
>
<
modelVersion
>4.0.0</
modelVersion
>
<
groupId
>com.favccxx.favsoft</
groupId
>
<
artifactId
>favspringmvcrestful</
artifactId
>
<
packaging
>war</
packaging
>
<
version
>0.0.1-SNAPSHOT</
version
>
<
name
>favspringmvcrestful Maven Webapp</
name
>
<
url
>http://maven.apache.org</
url
>
<
properties
>
<
spring.version
>4.1.1.RELEASE</
spring.version
>
<
jackson.version
>2.4.0</
jackson.version
>
</
properties
>
<
dependencies
>
<
dependency
>
<
groupId
>junit</
groupId
>
<
artifactId
>junit</
artifactId
>
<
version
>3.8.1</
version
>
<
scope
>test</
scope
>
</
dependency
>
<
dependency
>
<
groupId
>org.springframework</
groupId
>
<
artifactId
>spring-core</
artifactId
>
<
version
>${spring.version}</
version
>
</
dependency
>
<
dependency
>
<
groupId
>org.springframework</
groupId
>
<
artifactId
>spring-webmvc</
artifactId
>
<
version
>${spring.version}</
version
>
</
dependency
>
<
dependency
>
<
groupId
>org.springframework</
groupId
>
<
artifactId
>spring-beans</
artifactId
>
<
version
>${spring.version}</
version
>
</
dependency
>
<
dependency
>
<
groupId
>org.springframework</
groupId
>
<
artifactId
>spring-context</
artifactId
>
<
version
>${spring.version}</
version
>
</
dependency
>
<
dependency
>
<
groupId
>com.fasterxml.jackson.core</
groupId
>
<
artifactId
>jackson-core</
artifactId
>
<
version
>${jackson.version}</
version
>
</
dependency
>
<
dependency
>
<
groupId
>com.fasterxml.jackson.core</
groupId
>
<
artifactId
>jackson-annotations</
artifactId
>
<
version
>${jackson.version}</
version
>
</
dependency
>
<
dependency
>
<
groupId
>com.fasterxml.jackson.core</
groupId
>
<
artifactId
>jackson-databind</
artifactId
>
<
version
>${jackson.version}</
version
>
</
dependency
>
<
dependency
>
<
groupId
>jstl</
groupId
>
<
artifactId
>jstl</
artifactId
>
<
version
>1.2</
version
>
</
dependency
>
<
dependency
>
<
groupId
>taglibs</
groupId
>
<
artifactId
>standard</
artifactId
>
<
version
>1.1.2</
version
>
</
dependency
>
</
dependencies
>
<
build
>
<
finalName
>favspringmvcrestful</
finalName
>
</
build
>
</
project
>
|
3.在 web.xml中,配置Spring MVC 4 的DispatcherServlet转发和编码。
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<?
xml
version
=
"1.0"
encoding
=
"UTF-8"
?>
<
web-app
version
=
"2.4"
xmlns
=
"http://java.sun.com/xml/ns/j2ee"
xmlns:xsi
=
"http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<
display-name
>favblog</
display-name
>
<
context-param
>
<
param-name
>contextConfigLocation</
param-name
>
<
param-value
></
param-value
>
</
context-param
>
<
filter
>
<
filter-name
>encodingFilter</
filter-name
>
<
filter-class
>org.springframework.web.filter.CharacterEncodingFilter</
filter-class
>
<
init-param
>
<
param-name
>encoding</
param-name
>
<
param-value
>UTF-8</
param-value
>
</
init-param
>
<
init-param
>
<
param-name
>forceEncoding</
param-name
>
<
param-value
>true</
param-value
>
</
init-param
>
</
filter
>
<
filter-mapping
>
<
filter-name
>encodingFilter</
filter-name
>
<
url-pattern
>/*</
url-pattern
>
</
filter-mapping
>
<
listener
>
<
listener-class
>org.springframework.web.context.ContextLoaderListener</
listener-class
>
</
listener
>
<
servlet
>
<
servlet-name
>springMVC</
servlet-name
>
<
servlet-class
>org.springframework.web.servlet.DispatcherServlet</
servlet-class
>
<
init-param
>
<
param-name
>contextConfigLocation</
param-name
>
<
param-value
>classpath*:spring-context.xml</
param-value
>
</
init-param
>
<
load-on-startup
>1</
load-on-startup
>
</
servlet
>
<
servlet-mapping
>
<
servlet-name
>springMVC</
servlet-name
>
<
url-pattern
>/</
url-pattern
>
</
servlet-mapping
>
</
web-app
>
|
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<?
xml
version
=
"1.0"
encoding
=
"UTF-8"
?>
<
beans
xmlns
=
"http://www.springframework.org/schema/beans"
xmlns:xsi
=
"http://www.w3.org/2001/XMLSchema-instance"
xmlns:context
=
"http://www.springframework.org/schema/context"
xmlns:mvc
=
"http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">
<
context:component-scan
base-package
=
"com.favccxx.favsoft.favjson.controller"
></
context:component-scan
>
<
mvc:annotation-driven
></
mvc:annotation-driven
>
<
bean
id
=
"viewResolver"
class
=
"org.springframework.web.servlet.view.UrlBasedViewResolver"
>
<
property
name
=
"viewClass"
value
=
"org.springframework.web.servlet.view.JstlView"
/>
<
property
name
=
"prefix"
value
=
"/WEB-INF/views"
/>
<
property
name
=
"suffix"
value
=
".jsp"
/>
</
bean
>
</
beans
>
|
4.新建 FavUser.java 类,测试JSON与Object之间的映射。需要注意的是,如果想对日期进行格式化,在其Getter方法上,使用 @JsonFormat 即可,这样就能输出符合pattern类型的日期,但是这同时也要求输入的日期参数也必须是pattern类型的。
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package
com.favccxx.favsoft.favjson.pojo;
import
java.util.Date;
import
com.fasterxml.jackson.annotation.JsonFormat;
public
class
FavUser {
private
String userId;
private
String userName;
private
int
userAge;
private
Date createDate;
public
String getUserId() {
return
userId;
}
public
void
setUserId(String userId) {
this
.userId = userId;
}
public
String getUserName() {
return
userName;
}
public
void
setUserName(String userName) {
this
.userName = userName;
}
public
int
getUserAge() {
return
userAge;
}
public
void
setUserAge(
int
userAge) {
this
.userAge = userAge;
}
@JsonFormat
(pattern=
"yyyy-MM-dd HH:mm:ss"
)
public
Date getCreateDate() {
return
createDate;
}
public
void
setCreateDate(Date createDate) {
this
.createDate = createDate;
}
}
|
5. 新建FavRestfulController,通过不同的方法测试Spring MVC 4 返回String、Object类型的JSON。
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package
com.favccxx.favsoft.favjson.controller;
import
java.io.IOException;
import
org.springframework.web.bind.annotation.RequestBody;
import
org.springframework.web.bind.annotation.RequestMapping;
import
org.springframework.web.bind.annotation.RequestMethod;
import
org.springframework.web.bind.annotation.RequestParam;
import
org.springframework.web.bind.annotation.RestController;
import
com.fasterxml.jackson.core.JsonParseException;
import
com.fasterxml.jackson.databind.JsonMappingException;
import
com.fasterxml.jackson.databind.ObjectMapper;
import
com.favccxx.favsoft.favjson.pojo.FavUser;
@RestController
public
class
FavRestfulController {
@RequestMapping
(value=
"/getUserName"
,method=RequestMethod.POST)
public
String getUserName(
@RequestParam
(value=
"name"
) String name){
return
name;
}
@RequestMapping
(
"getFavUser"
)
public
FavUser getFavUser(
@RequestParam
(
"userName"
) String userName,String userId,
int
userAge){
FavUser favUser =
new
FavUser();
favUser.setUserId(userId);
favUser.setUserName(userName);
favUser.setUserAge(userAge);
return
favUser;
}
@RequestMapping
(
"getFavUserBody"
)
public
FavUser getFavUserBody(
@RequestBody
String body){
ObjectMapper mapper =
new
ObjectMapper();
FavUser favUser =
null
;
try
{
favUser = mapper.readValue(body, FavUser.
class
);
}
catch
(JsonParseException e) {
e.printStackTrace();
}
catch
(JsonMappingException e) {
e.printStackTrace();
}
catch
(IOException e) {
e.printStackTrace();
}
return
favUser;
}
}
|
6.运行结果如下: