springmvc Controller接收前端参数的几种方式总结
(1) 普通方式-请求参数名和Controller方法的参数一致
1 @Controller 2 @RequestMapping("/param") 3 public class TestParamController { 4 private static final Logger logger = LoggerFactory.getLogger(TestParamController.class); 5 /** 6 * 请求参数名和Controller方法的参数一致 7 * produces 设置返回参数的编码格式可以设置返回数据的类型以及编码,可以是json或者xml 8 * { 9 * @RequestMapping(value="/xxx",produces = {"application/json;charset=UTF-8"}) 10 * 或 11 * @RequestMapping(value="/xxx",produces = {"application/xml;charset=UTF-8"}) 12 * 或 13 * @RequestMapping(value="/xxx",produces = "{text/html;charset=utf-8}") 14 * } 15 * @param name 用户名 16 * @param pwd 密码 17 * @return 18 * 19 */ 20 @RequestMapping(value = "/add", method = RequestMethod.GET, produces = {"application/json;charset=UTF-8"}) 21 @ResponseBody 22 public String addUser(String name, String pwd){ 23 logger.debug("name:" + name + ",pwd:" + pwd); 24 return "name:" + name + ",pwd:" + pwd; 25 } 26 27 }
如下图所示:
通过访问:http://localhost:8080/sty/param/add.action?name=张三&pwd=123456
(2) 对象方式-请求参数名和Controller方法中的对象的参数一致
@Controller @RequestMapping("/param") public class TestParamController { private static final Logger logger = LoggerFactory.getLogger(TestParamController.class); /** * 请求参数名和Controller方法的参数一致 * produces 设置返回参数的编码格式可以设置返回数据的类型以及编码,可以是json或者xml * } * @param user 用户信息 * @return * */ @RequestMapping(value = "/addByObject", method = RequestMethod.GET, produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUserByObject(User user){ logger.debug("name:" + user.getName() + ",pwd:" + user.getPwd()); return "name:" + user.getName() + ",pwd:" + user.getPwd(); } }
如下图所示:
通过访问:http://localhost:8080/sty/param/addByObject.action?name=张三&pwd=123456 。
(3) 自定义方法参数名-当请求参数名与方法参数名不一致时
注意可以在参数中增加@RequestParam注解。如果在方法中的参数增加了该注解,说明请求的url必须带该带有该参数,否则不能执行该方法。如果在方法中的参数没有增加该注解,说明请求的url无需带有该参数,也能继续执行该方法。
@RequestParam(defaultValue="0")可设置默认值(仅当传入参数为空时)。
@RequestParam(value="id")可接受传入参数为id的值,覆盖该注解注释的字段。
@RequestParam(name="name",defaultValue = "李四") String u_name 如果传入字段”name”为空,默认u_name的值为”李四”。若传入”name”不为空,默认u_name值为传入值。
以下只该出方法:
/** * 自定义方法参数名-当请求参数名与方法参数名不一致时 * @param u_name 用户名 * @param u_pwd 密码 * @return */ @RequestMapping(value = "/addByDifName", method = RequestMethod.GET, produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUserByDifName(@RequestParam("name") String u_name, @RequestParam("pwd")String u_pwd){ logger.debug("name:" + u_name + ",pwd:" + u_pwd); return "name:" + u_name + ",pwd:" + u_pwd; }
如下图所示:
通过访问:http://localhost:8080/sty/param/addUserByDifName.action?name=张三&pwd=123456 。
(4) HttpServletRequest方式
以下只给出该方法:
/** * 通过HttpServletRequest接收 * @param request * @return */ @RequestMapping(value = "/addByHttpServletRequest", method = RequestMethod.GET, produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUserByHttpServletRequest(HttpServletRequest request){ String name = request.getParameter("name"); String pwd = request.getParameter("pwd"); logger.debug("name:" + name + ",pwd:" + pwd); return "name:" + name + ",pwd:" + pwd; }
如下图所示:
通过访问:http://localhost:8080/sty/param/addByHttpServletRequest.action?name=张三&pwd=123456
(5) @PathVariable获取路径中的参数接收
参考:https://www.iteye.com/blog/zhlj11-1885005 。
注:url含有中文名称时,因为编码问题,无法进行映射,需要修改tomcat下的conf文件夹下的server.xml中的URIEncoding=”UTF-8”,对URL编码设置就可以解决中文问题。
对于经常遇到路径在有符号”.”问题,因为springmvc默认是把点后面的信息作为文件后缀,需要修改默认值:
<bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping">
<property name="interceptors" ref="localeChangeInterceptor"/>
<property name="useDefaultSuffixPattern" value="false" />
</bean>
另外,这时候如果只设置这个,请求可以传递到对于的controller,但传过去的数据会有问题,只会传最后一个点前面的数据,除非你在最后加上“/”,比如/news/测试.点/ 这样就会把“测试.点”当作整体,不然只会得到“测试”。这时候我们可以这样设置@RequestMapping("/news/{title:.*}")
以下只给出该方法(本次不进行中文及特殊符号测试):
/** * 通过@PathVariable获取路径中的参数 * @param name 用户名 * @param pwd 密码 * @return */ @RequestMapping(value = "/add/{name}/{pwd}", method = RequestMethod.GET, produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUserByPathVariable(@PathVariable String name, @PathVariable String pwd){ logger.debug("name:" + name + ",pwd:" + pwd); return "name:" + name + ",pwd:" + pwd; }
如下图所示:
通过访问:http://localhost:8080/sty/param/add/zhangsan/123456.action
(6) @RequestBody-JSON方式接收
以上方式(1)/(2)/)(3)/(4)/(5)都是非JSON方式,也就是说如果使用JSON方式提交,会报错(在第二种对象方式中,将get请求方式修改为POST,并将上送数据修改为JSON串方式):
此时未引入jackson-databind.jar依赖。并在springmvc.xml文件未进行开启json格式的支持,也就是说未加入以下代码:
<!-- 同时开启json格式的支持--> <mvc:annotation-driven></mvc:annotation-driven>
提交请求打印未有报错,但是返回的数据为null,如图所示:
若开启json格式的支持,测试也如上图所示,也并能正常返回。
原因:因为为在字段名称之前未使用@RequestBody注解。
eg1(测试普通对象)
代码如下所示,
/** * RequestBody-JSON 对象方式 * @param user * @return */ @RequestMapping(value = "/addByObjectJSON", produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUserByObjectJSON(@RequestBody User user){ logger.debug("name:" + user.getName() + ",pwd:" + user.getPwd()); return "name:" + user.getName() + ",pwd:" + user.getPwd(); }
测试结果如图所示(访问 http://localhost:8080/sty/param/addByObjectJSON.action ):
eg2(测试List对象)
代码如下所示,
/** * RequestBody-JSON List对象方式 * @param users * @return */ @RequestMapping(value = "/addByListJSON", produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUsersByListJSON(@RequestBody List<User> users){ StringBuilder sb = new StringBuilder("{"); if(null != users){ for(User user : users){ sb.append("{" + "name:" + user.getName() + ",pwd:" + user.getPwd() + "}"); } } sb.append("}"); logger.debug(sb.toString()); return sb.toString(); }
测试结果
测试结果如图所示(访问 http://localhost:8080/sty/param/addByListJSON.action ):
eg3(测试Map对象)
代码如下图所示:
/** * RequestBody-JSON Map对象方式 * @param users * @return */ @RequestMapping(value = "/addByMapJSON", produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUsersByMapJSON(@RequestBody Map<String, User> users){ StringBuilder sb = new StringBuilder("{"); if(null != users){ Iterator it = users.keySet().iterator(); while(it.hasNext()){ User user = users.get(it.next()); sb.append("{" + "name:" + user.getName() + ",pwd:" + user.getPwd() + "}"); } } sb.append("}"); logger.debug(sb.toString()); return sb.toString(); }
测试结果
测试结果如图所示(访问 http://localhost:8080/sty/param/addByMapJSON.action ):
另外附部分源码:
User.java
package com.mjs.study.action.dto; /** * @Description * @ClassName User * @Author Administrator * @Data 2019/10/13 2:43 * @Version 1.0 */ public class User { private String name; private String pwd; private String sex; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getPwd() { return pwd; } public void setPwd(String pwd) { this.pwd = pwd; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } }
TestParamController.java
package com.mjs.study.action; import com.github.pagehelper.PageInfo; import com.mjs.study.action.dto.User; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.*; import javax.servlet.http.HttpServletRequest; import java.util.Iterator; import java.util.List; import java.util.Map; /** * @Description 测试springmvc传入参数 * @ClassName TestParamController * @Author Administrator * @Data 2019/10/13 1:33 * @Version 1.0 */ @Controller @RequestMapping("/param") public class TestParamController { private static final Logger logger = LoggerFactory.getLogger(TestParamController.class); /** * 请求参数名和Controller方法的参数一致 * produces 设置返回参数的编码格式 可以设置返回数据的类型以及编码,可以是json或者xml * { * @RequestMapping(value="/xxx",produces = {"application/json;charset=UTF-8"}) * 或 * @RequestMapping(value="/xxx",produces = {"application/xml;charset=UTF-8"}) * 或 * @RequestMapping(value="/xxx",produces = "{text/html;charset=utf-8}") * } * @param name 用户名 * @param pwd 密码 * @return * */ @RequestMapping(value = "/add", method = RequestMethod.GET, produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUser(String name, String pwd){ logger.debug("name:" + name + ",pwd:" + pwd); return "name:" + name + ",pwd:" + pwd; } /** * 自定义方法参数名-当请求参数名与方法参数名不一致时 * @param u_name 用户名 * @param u_pwd 密码 * @return */ @RequestMapping(value = "/addByDifName", method = RequestMethod.GET, produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUserByDifName(@RequestParam(name="name",defaultValue = "李四") String u_name, @RequestParam("pwd")String u_pwd){ logger.debug("name:" + u_name + ",pwd:" + u_pwd); return "name:" + u_name + ",pwd:" + u_pwd; } /** * 请求参数名和Controller方法的参数一致 * produces 设置返回参数的编码格式 可以设置返回数据的类型以及编码,可以是json或者xml * @param user 用户信息 * @return * */ @RequestMapping(value = "/addByObject", produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUserByObject(User user){ logger.debug("name:" + user.getName() + ",pwd:" + user.getPwd()); return "name:" + user.getName() + ",pwd:" + user.getPwd(); } /** * RequestBody-JSON 对象方式 * @param user * @return */ @RequestMapping(value = "/addByObjectJSON", produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUserByObjectJSON(@RequestBody User user){ logger.debug("name:" + user.getName() + ",pwd:" + user.getPwd()); return "name:" + user.getName() + ",pwd:" + user.getPwd(); } /** * RequestBody-JSON List对象方式 * @param users * @return */ @RequestMapping(value = "/addByListJSON", produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUsersByListJSON(@RequestBody List<User> users){ StringBuilder sb = new StringBuilder("{"); if(null != users){ for(User user : users){ sb.append("{" + "name:" + user.getName() + ",pwd:" + user.getPwd() + "}"); } } sb.append("}"); logger.debug(sb.toString()); return sb.toString(); } /** * RequestBody-JSON Map对象方式 * @param users * @return */ @RequestMapping(value = "/addByMapJSON", produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUsersByMapJSON(@RequestBody Map<String, User> users){ StringBuilder sb = new StringBuilder("{"); if(null != users){ Iterator it = users.keySet().iterator(); while(it.hasNext()){ User user = users.get(it.next()); sb.append("{" + "name:" + user.getName() + ",pwd:" + user.getPwd() + "}"); } } sb.append("}"); logger.debug(sb.toString()); return sb.toString(); } /** * 通过HttpServletRequest接收 * @param request * @return */ @RequestMapping(value = "/addByHttpServletRequest", method = RequestMethod.GET, produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUserByHttpServletRequest(HttpServletRequest request){ String name = request.getParameter("name"); String pwd = request.getParameter("pwd"); logger.debug("name:" + name + ",pwd:" + pwd); return "name:" + name + ",pwd:" + pwd; } /** * 通过@PathVariable获取路径中的参数 * @param name 用户名 * @param pwd 密码 * @return */ @RequestMapping(value = "/add/{name}/{pwd}", method = RequestMethod.GET, produces = {"application/json;charset=UTF-8"}) @ResponseBody public String addUserByPathVariable(@PathVariable String name, @PathVariable String pwd){ logger.debug("name:" + name + ",pwd:" + pwd); return "name:" + name + ",pwd:" + pwd; } }
该部分和个人github部分内容同步。