@RequestBody傳遞多個不同對象
如果使用spring mvc同客戶端通信，完全使用json數據格式，需要增加RequestBody注解，函數參數為自定義類
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@Controllerpublic class TestController{ @RequestMapping("\test") @ResponseBody public RetureResult test(@RequestBody User user){ return new ReturnResult(); } } |
這樣的話，可以將接收到的json格式的數據轉換為指定的數據對象user。比如{name:"test"}，name為User類的屬性域。通過ResponseBody注解，可以返回json格式的數據。
有時接收json格式數據時，我們可能需要將其轉換為多個對象。
以下方式是錯誤的。原因是request的content-body是以流的形式進行讀取的，讀取完一次后，便無法再次讀取了。
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@Controllerpublic class TestController{ @RequestMapping("\test") @ResponseBody public RetureResult test(@RequestBody User user,@RequestBody Address address){ return new ReturnResult(); } } |
解決方案1
增加一個包裝類，將所需要類寫入，增加get，set方法
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@Controllerpublic class TestController{ @RequestMapping("\test") @ResponseBody public RetureResult test(@RequestBody Param param){ User user=param.getUser(); Address address=param.getAddress(); return new ReturnResult(); } }class Param{ private User user; private Address address; public User getUser() { return user; } public void setUser(User user) { this.user = user; } public Address getAddress() { return address; } public void setAddress(Address address) { this.address = address; }} |
此時傳輸的json數據格式變為{user:{name:"test"},address:{location:"新華路"}}。
由于只是在TestController中增加一個包裝類，不會影響其他的類以及已經定義好的model類，因此可以非常方便的達到接收多個對象參數的目的。
解決方案2
將接收參數定義為Map<String, Object>，然后使用map轉object工具，轉換成需要的對象。
此時，即使自定義的Param類中的屬性即使比json數據中的屬性少了，也沒關系。
其中JSONUtils為自定義的工具類，可使用常見的fastjson等工具包包裝實現。
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@Controllerpublic class TestController{ @RequestMapping("\test") @ResponseBody public Object test(@RequestBody Map<String, Object> models){ User user=JsonXMLUtils.map2object((Map<String, Object>)models.get("user"),User.class); Address address=JsonXMLUtils.map2object((Map<String, Object>)models.get("address"),Address.class); return models; }}import com.alibaba.fastjson.JSON; public class JsonXMLUtils { public static String obj2json(Object obj) throws Exception { return JSON.toJSONString(obj); } public static <T> T json2obj(String jsonStr, Class<T> clazz) throws Exception { return JSON.parseObject(jsonStr, clazz); } public static <T> Map<String, Object> json2map(String jsonStr) throws Exception { return JSON.parseObject(jsonStr, Map.class); } public static <T> T map2obj(Map<?, ?> map, Class<T> clazz) throws Exception { return JSON.parseObject(JSON.toJSONString(map), clazz); }} |
使用多個@RequestBody接收參數
原因
常規情況下，因為request的body只能讀取一次，@RequestBody也只能解析一次，這就導致解析第二個的@RequestBody的時候stream已經關閉了，無法再次讀取。
話不多說，上貨：
解決辦法：兩個類，直接copy即可
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import javax.servlet.ReadListener;import javax.servlet.ServletInputStream;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletRequestWrapper;import java.io.*; public class BodyReaderRequestWrapper extends HttpServletRequestWrapper { private final String body; /** * * @param request */ public BodyReaderRequestWrapper(HttpServletRequest request) throws IOException{ super(request); StringBuilder sb = new StringBuilder(); InputStream ins = request.getInputStream(); BufferedReader isr = null; try{ if(ins != null){ isr = new BufferedReader(new InputStreamReader(ins)); char[] charBuffer = new char[128]; int readCount = 0; while((readCount = isr.read(charBuffer)) != -1){ sb.append(charBuffer,0,readCount); } }else{ sb.append(""); } }catch (IOException e){ throw e; }finally { if(isr != null) { isr.close(); } } sb.toString(); body = sb.toString(); } @Override public BufferedReader getReader() throws IOException { return new BufferedReader(new InputStreamReader(this.getInputStream())); } @Override public ServletInputStream getInputStream() throws IOException { final ByteArrayInputStream byteArrayIns = new ByteArrayInputStream(body.getBytes()); ServletInputStream servletIns = new ServletInputStream() { @Override public boolean isFinished() { return false; } @Override public boolean isReady() { return false; } @Override public void setReadListener(ReadListener readListener) { } @Override public int read() throws IOException { return byteArrayIns.read(); } }; return servletIns; }} |
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import org.springframework.stereotype.Component; import javax.servlet.*;import javax.servlet.annotation.WebFilter;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException; @Component@WebFilter(filterName = "crownFilter", urlPatterns = "/*")public class BodyReaderRequestFilter implements Filter { @Override public void init(FilterConfig filterConfig) throws ServletException { } @Override public void doFilter(ServletRequest req, ServletResponse res, FilterChain filterChain) throws IOException, ServletException { HttpServletRequest request = (HttpServletRequest)req; HttpServletResponse response = (HttpServletResponse)res; BodyReaderRequestWrapper requestWrapper = new BodyReaderRequestWrapper(request); if(requestWrapper == null){ filterChain.doFilter(request,response); }else { filterChain.doFilter(requestWrapper,response); } } @Override public void destroy() { }} |
使用：自行測試。
以上為個人經驗，希望能給大家一個參考，也希望大家多多支持服務器之家。
原文鏈接：https://blog.csdn.net/sunayn/article/details/106214391
