閒話少說,剛開始用SpringMVC, 頁面要使用jquery的ajax請求Controller。 但老是失敗,主要表現爲如下兩個異常爲:javascript
異常一:java.lang.ClassNotFoundException: org.springframework.http.converter.json.MappingJacksonHttpMessageConverterhtml
異常二:SpringMVC @ResponseBody 415錯誤處理java
網上分析緣由不少,但找了好久都沒解決,基本是如下幾類:jquery
- springmvc添加配置、註解;
- pom.xml添加jackson包引用;
- Ajax請求時沒有設置Content-Type爲application/json
- 發送的請求內容不要轉成JSON對象,直接發送JSON字符串便可
這些其實都沒錯!!!web
如下是我分析的解決步驟方法:ajax
(1)springMVC配置文件開啓註解spring
- <mvc:annotation-driven />
(2)添加springMVC須要添加以下配置。 (這個要注意spring版本,3.x和4.x配置不一樣)json
spring3.x是org.springframework.http.converter.json.MappingJacksonHttpMessageConverter瀏覽器
spring4.x是org.springframework.http.converter.json.MappingJackson2HttpMessageConvertermvc
具體能夠查看spring-web的jar確認,哪一個存在用哪一個!
spring3.x配置:
- <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
- <property name="messageConverters">
- <list>
- <ref bean="jsonHttpMessageConverter" />
- </list>
- </property>
- </bean>
-
- <bean id="jsonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
- <property name="supportedMediaTypes">
- <list>
- <value>application/json;charset=UTF-8</value>
- </list>
- </property>
- </bean>
spring4.x配置:
- <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
- <property name="messageConverters">
- <list>
- <ref bean="jsonHttpMessageConverter" />
- </list>
- </property>
- </bean>
-
- <bean id="jsonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
- <property name="supportedMediaTypes">
- <list>
- <value>application/json;charset=UTF-8</value>
- </list>
- </property>
- </bean>
(3)pom.xml添加jackson依賴(這個要注意spring版本,3.x和4.x配置不一樣)
若是是spring 3.x,pom.xml添加以下配置
- <dependency>
- <groupId>org.codehaus.jackson</groupId>
- <artifactId>jackson-core-lgpl</artifactId>
- <version>1.8.1</version>
- </dependency>
-
-
- <dependency>
- <groupId>org.codehaus.jackson</groupId>
- <artifactId>jackson-mapper-lgpl</artifactId>
- <version>1.8.1</version>
- </dependency></span>
spring4.x, pom.xml添加以下配置
- <dependency>
- <groupId>com.fasterxml.jackson.core</groupId>
- <artifactId>jackson-core</artifactId>
- <version>2.5.2</version>
- </dependency>
-
- <dependency>
- <groupId>com.fasterxml.jackson.core</groupId>
- <artifactId>jackson-databind</artifactId>
- <version>2.5.2</version>
- </dependency>
這裏要說明一下,spring3.x用的是org.codehaus.jackson的1.x版本,在maven資源庫,已經不在維護,統一遷移到com.fasterxml.jackson,版本對應爲2.x
(4)ajax請求要求
- dataType 爲 json
- contentType 爲 'application/json;charse=UTF-8'
- data 轉JSON字符串
個人代碼:以下: (注意:這裏只是針對POST +JSON字符串形式請求,後面我會詳細講解不一樣形式請求,的處理方法和案例)
- var data = {
- userAccount: lock_username,
- userPasswd:hex_md5(lock_password).toUpperCase()
- }
-
- $.ajax({
- url : ctx + "/unlock.do",
- type : "POST",
- data : JSON.stringify(data),
- dataType: 'json',
- contentType:'application/json;charset=UTF-8',
- success : function(result) {
- console.log(result);
- }
- });
(5) Controller 接收響應JSON
以上配置OK,Controller中使用JSON方式有多種。這裏簡單介紹幾種。
這個關鍵在於ajax請求是將數據以什麼形式傳遞到後臺,這裏我總結了三種形式
- POST + JSON字符串形式
- POST + JSON對象形式
- GET + 參數字符串
- 方式一: POST + JSON字符串形式,以下:
- var data = {
- userAccount: lock_username,
- userPasswd:hex_md5(lock_password).toUpperCase()
- }
-
- $.ajax({
- url : ctx + "/unlock.do",
- type : "POST",
- data : JSON.stringify(data),
- dataType: 'json',
- contentType:'application/json;charset=UTF-8',
- success : function(result) {
- console.log(result);
- }
- });
- ar data = {
- userAccount: lock_username,
- userPasswd:hex_md5(lock_password).toUpperCase()
- }
-
- $.ajax({
- url : ctx + "/unlock.do",
- type : "POST",
- data : data,
- dataType: 'json',
- success : function(result) {
- console.log(result);
- }
- });
代碼案例:
5-1: 使用@RequestBody來設置輸入 ,@ResponseBody設置輸出 (POST + JSON字符串形式)
JS請求:
- var data = {
- userAccount: lock_username,
- userPasswd:hex_md5(lock_password).toUpperCase()
- }
-
- $.ajax({
- url : ctx + "/unlock.do",
- type : "POST",
- data : JSON.stringify(data),
- dataType: 'json',
- contentType:'application/json;charset=UTF-8',
- success : function(result) {
- console.log(result);
- }
- });
Controller處理:
- @RequestMapping(value = "/unlock", method = RequestMethod.POST,consumes = "application/json")
- @ResponseBody
- public Object unlock(@RequestBody User user) {
- JSONObject jsonObject = new JSONObject();
-
- try{
- Assert.notNull(user.getUserAccount(), "解鎖帳號爲空");
- Assert.notNull(user.getUserPasswd(), "解鎖密碼爲空");
-
- User currentLoginUser = (User) MvcUtils.getSessionAttribute(Constants.LOGIN_USER);
- Assert.notNull(currentLoginUser, "登陸用戶已過時,請從新登陸!");
-
- Assert.isTrue(StringUtils.equals(user.getUserAccount(),currentLoginUser.getUserAccount()), "解鎖帳號錯誤");
- Assert.isTrue(StringUtils.equalsIgnoreCase(user.getUserPasswd(),currentLoginUser.getUserPasswd()), "解鎖密碼錯誤");
-
- jsonObject.put("message", "解鎖成功");
- jsonObject.put("status", "success");
- }catch(Exception ex){
- jsonObject.put("message", ex.getMessage());
- jsonObject.put("status", "error");
- }
- return jsonObject;
- }
5-2: 使用HttpEntity來實現輸入綁定,來ResponseEntit輸出綁定(POST + JSON字符串形式)
JS請求:
- var data = {
- userAccount: lock_username,
- userPasswd:hex_md5(lock_password).toUpperCase()
- }
-
- $.ajax({
- url : ctx + "/unlock.do",
- type : "POST",
- data : JSON.stringify(data),
- dataType: 'json',
- contentType:'application/json;charset=UTF-8',
- success : function(result) {
- console.log(result);
- }
- });
Controller處理:
- @RequestMapping(value = "/unlock", method = RequestMethod.POST,consumes = "application/json")
- public ResponseEntity<Object> unlock(HttpEntity<User> user) {
- JSONObject jsonObject = new JSONObject();
-
- try{
- Assert.notNull(user.getBody().getUserAccount(), "解鎖帳號爲空");
- Assert.notNull(user.getBody().getUserPasswd(), "解鎖密碼爲空");
-
- User currentLoginUser = (User) MvcUtils.getSessionAttribute(Constants.LOGIN_USER);
- Assert.notNull(currentLoginUser, "登陸用戶已過時,請從新登陸!");
-
- Assert.isTrue(StringUtils.equals(user.getBody().getUserAccount(),currentLoginUser.getUserAccount()), "解鎖帳號錯誤");
- Assert.isTrue(StringUtils.equalsIgnoreCase(user.getBody().getUserPasswd(),currentLoginUser.getUserPasswd()), "解鎖密碼錯誤");
-
- jsonObject.put("message", "解鎖成功");
- jsonObject.put("status", "success");
- }catch(Exception ex){
- jsonObject.put("message", ex.getMessage());
- jsonObject.put("status", "error");
- }
- ResponseEntity<Object> responseResult = new ResponseEntity<Object>(jsonObject,HttpStatus.OK);
- return responseResult;
- }
5-3: 使用request.getParameter獲取請求參數,響應JSON(POST + JSON對象形式) 和(GET + 參數字符串),Controller處理同樣,區別在因而否加註解method ,
若是不加適用GET + POST ;
若是 method= RequestMethod.POST,用於POST 請求;
若是method=RequestMethod.GET,用於GET請求;
POST+ JSON對象形式請求:
- var data = {
- userAccount: lock_username,
- userPasswd:hex_md5(lock_password).toUpperCase()
- }
-
- $.ajax({
- url : ctx + "/unlock.do",
- type : "POST",
- data : data,
- dataType: 'json',
- success : function(result) {
- console.log(result);
- }
- });
GET + 參數字符串請求:
- $.ajax({
- url : ctx + "/unlock.do",
- type : "GET",
- dataType: "text",
- data : "userAccount="+lock_username+"&userPasswd=" + hex_md5(lock_password).toUpperCase(),
- success : function(result) {
- console.log(result);
- }
- });
Controller處理:
- @RequestMapping(value = "/unlock")
- public void unlock(HttpServletRequest request,HttpServletResponse response) throws IOException {
- JSONObject jsonObject = new JSONObject();
-
- String userAccount = (String)request.getParameter("userAccount");
- String userPasswd = (String)request.getParameter("userPasswd");
- try{
- Assert.notNull(userAccount, "解鎖帳號爲空");
- Assert.notNull(userPasswd, "解鎖密碼爲空");
-
- User currentLoginUser = (User) MvcUtils.getSessionAttribute(Constants.LOGIN_USER);
- Assert.notNull(currentLoginUser, "登陸用戶已過時,請從新登陸!");
-
- Assert.isTrue(StringUtils.equals(userAccount,currentLoginUser.getUserAccount()), "解鎖帳號錯誤");
- Assert.isTrue(StringUtils.equalsIgnoreCase(userPasswd,currentLoginUser.getUserPasswd()), "解鎖密碼錯誤");
-
- jsonObject.put("message", "解鎖成功");
- jsonObject.put("status", "success");
- }catch(Exception ex){
- jsonObject.put("message", ex.getMessage());
- jsonObject.put("status", "error");
- }
-
- response.getWriter().print(jsonObject.toString());
- }
5-4: 使用@ModelAttribute將參數封裝對象,響應JSON(POST + JSON對象形式) 和(GET + 參數字符串),Controller處理同樣,區別在因而否加註解method 。
若是不加適用GET + POST ;
若是 method= RequestMethod.POST,用於POST 請求;
若是method=RequestMethod.GET,用於GET請求;
POST+ JSON對象形式請求:
- var data = {
- userAccount: lock_username,
- userPasswd:hex_md5(lock_password).toUpperCase()
- }
-
- $.ajax({
- url : ctx + "/unlock.do",
- type : "POST",
- data : data,
- dataType: 'json',
- success : function(result) {
- console.log(result);
- }
- });
GET + 參數字符串請求:
- $.ajax({
- url : ctx + "/unlock.do",
- type : "GET",
- dataType: "text",
- data : "userAccount="+lock_username+"&userPasswd=" + hex_md5(lock_password).toUpperCase(),
- success : function(result) {
- console.log(result);
- }
- });
Controller處理:(這個案例只支持POST)
- @RequestMapping(value = "/unlock",method = RequestMethod.POST)
- public void unlock(@ModelAttribute("user") User user,PrintWriter printWriter) throws IOException {
- JSONObject jsonObject = new JSONObject();
-
- try{
- Assert.notNull(user.getUserAccount(), "解鎖帳號爲空");
- Assert.notNull(user.getUserPasswd(), "解鎖密碼爲空");
-
- User currentLoginUser = (User) MvcUtils.getSessionAttribute(Constants.LOGIN_USER);
- Assert.notNull(currentLoginUser, "登陸用戶已過時,請從新登陸!");
-
- Assert.isTrue(StringUtils.equals(user.getUserAccount(),currentLoginUser.getUserAccount()), "解鎖帳號錯誤");
- Assert.isTrue(StringUtils.equalsIgnoreCase(user.getUserPasswd(),currentLoginUser.getUserPasswd()), "解鎖密碼錯誤");
-
- jsonObject.put("message", "解鎖成功");
- jsonObject.put("status", "success");
- }catch(Exception ex){
- jsonObject.put("message", ex.getMessage());
- jsonObject.put("status", "error");
- }
- printWriter.print(jsonObject.toString());
- }