java.lang.ClassCastException：java.util.LinkedHashMap中不能鑄造

Question

的javascript

$.ajax({  
    headers : { 
     'Accept' : 'application/json' , 
     'Content-Type' : 'application/json' 
    }, 
    url   : "/realgrid/product/addOd.do", 
    type  : "post", 
    data  : JSON.stringify(JsonOrderDetailValues), 
    dataType : "json", 
    success  : function(data){ 
     var json = eval(data); 
     if (json.result == 1) { 
       alert("insert."); 
     }else if(json.result == 2){ 
       alert("update.") 
     }else { 
      alert("error."); 
     } 
    }, 
    error : function(request,status,error){ 
     alert("code:"+request.status+"\n"+"error:"+error); 
    } 
}); 

的console.log（JsonOrderDetailValues）

[Object, Object, Object, Object] 
0: Object 
categoryCode: "AC-MV" 
categoryName: undefined 
costPrice: 168050 
date: undefined 
modelCode: "YP-GB70" 
modelName: undefined 
no: 1 
number: "201309120932" 
total: 88 
totalPrice: 14788400 
typeCode: "AV" 
typeName: undefined 
unitPrice: 294500 
__proto__: Object 
1: Object 
2: Object 
3: Object 

java的彈簧控制器

@RequestMapping (value="/addOd.do",method=RequestMethod.POST) 
public ModelAndView addOdMaster(@RequestBody List<OrderDetails> od){ 

     //java.lang.ClassCastException: java.util.LinkedHashMap cannot be cast 
    System.out.println(od.get(0).getNumber()); 

    Map<String, Integer> result = new HashMap<String,Integer>(); 
    result.put("result", 0); 
    return new ModelAndView("jsonView",result); 
} 

VO

public class OrderDetails { 
private String number; 
private int no; 
private String typeCode; 
private String categoryCode; 
private String modelCode; 
private int total; 
private int costPrice; 
private int unitPrice; 
private int totalPrice; 


public int getTotalPrice() { 
    return totalPrice; 
} 
public void setTotalPrice(int totalPrice) { 
    this.totalPrice = totalPrice; 
} 
public String getNumber() { 
    return number; 
} 
public void setNumber(String number) { 
    this.number = number; 
} 
public int getNo() { 
    return no; 
} 
public void setNo(int no) { 
    this.no = no; 
} 
public String getTypeCode() { 
    return typeCode; 
} 
public void setTypeCode(String typeCode) { 
    this.typeCode = typeCode; 
} 
public String getCategoryCode() { 
    return categoryCode; 
} 
public void setCategoryCode(String categoryCode) { 
    this.categoryCode = categoryCode; 
} 
public String getModelCode() { 
    return modelCode; 
} 
public void setModelCode(String modelCode) { 
    this.modelCode = modelCode; 
} 
public int getTotal() { 
    return total; 
} 
public void setTotal(int total) { 
    this.total = total; 
} 
public int getCostPrice() { 
    return costPrice; 
} 
public void setCostPrice(int costPrice) { 
    this.costPrice = costPrice; 
} 
public int getUnitPrice() { 
    return unitPrice; 
} 
public void setUnitPrice(int unitPrice) { 
    this.unitPrice = unitPrice; 
} 
} 

錯誤信息

FATAL: Servlet.service() for servlet [dispatcher] in context with path [/realgrid] threw exception [Request processing failed; nested exception is java.lang.ClassCastException: java.util.LinkedHashMap cannot be cast to com.realgrid.productControl.model.OrderDetails] with root cause 
java.lang.ClassCastException: java.util.LinkedHashMap cannot be cast to com.realgrid.productControl.model.OrderDetails 
    at com.realgrid.productControl.controller.ProductControlController.addOdMaster(ProductControlController.java:181) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) 
    at java.lang.reflect.Method.invoke(Unknown Source) 
    at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:213) 
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:126) 
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:96) 
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:617) 
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:578) 
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80) 
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923) 
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852) 
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882) 
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:641) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) 
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164) 
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164) 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100) 
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562) 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395) 
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250) 
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188) 
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) 
    at java.lang.Thread.run(Unknown Source) 

爲什麼不呢？

Answer 1

在舊版本的春天，春天不能（或者說不會）確定

@RequestBody List<OrderDetails> od 

有一個泛型類型OrderDetails，因此傑克遜（JSON的解串器）的會用LinkedHashMap作爲默認類型。類型安全性會因您的情況而中斷，因爲所有這些整個請求處理調用（@RequestMapping方法及其參數）都是通過反射完成的。

的解決方案，這些版本是創建自己的類型

public class OrderDetailsList extends ArrayList<OrderDetails> {} 

和使用，作爲一個參數

@RequestBody OrderDetailsList od 

（或升級到春天4）