将 JSON 字符串转换为 java 中不同的 java 对象
Convert JSON String to different java Objects in java
我对将 JSON 字符串转换为不同的对象有疑问。
我的要求是我必须获取一个 JSON 字符串，然后我必须从该字符串中获取值并将其保存在 Postgresql 数据库中。
我的JSON字符串是
"followup":[{ "Active" : 1,
"NextVisit" : "Yes",
"CreateDate" : "12/17/2014 02:53:43 PM",
"Designation" : "Yes",
"ModifiedDate" : "12/17/2014 02:53:43 PM",
"flag" : "I"
},
"identity":[{ "Active" : 1,
"Createdate" : "12/17/2014 02:45:12 PM",
"DistrictID" : "01",
"HouseNo" : 3456,
"Code" : 22,
"ModifiedDate" : "12/17/2014 02:45:12 PM",
"flag" : "I"
}]
我制作了 2 个实体类，即 followup 和 identity，其变量与 Json String
中的变量相同
我的代码是：
Gson gson = new Gson();
identity hhIden =gson.fromJson(jsonString, identity .class);
followup ls=gson.fromJson(jsonString, followup .class);
我在 netbeans 中遇到以下异常：
java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 14
com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 14
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:176)
at com.google.gson.Gson.fromJson(Gson.java:795)
at com.google.gson.Gson.fromJson(Gson.java:761)
at com.google.gson.Gson.fromJson(Gson.java:710)
at com.google.gson.Gson.fromJson(Gson.java:682)
at server.NewWebService.hello(NewWebService.java:59)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.glassfish.webservices.InstanceResolverImpl.invoke(InstanceResolverImpl.java:144)
at com.sun.xml.ws.server.InvokerTube.invoke(InvokerTube.java:149)
at com.sun.xml.ws.server.sei.SEIInvokerTube.processRequest(SEIInvokerTube.java:88)
at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:1136)
at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:1050)
at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:1019)
at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:877)
at com.sun.xml.ws.api.pipe.helper.AbstractTubeImpl.process(AbstractTubeImpl.java:136)
at org.glassfish.webservices.MonitoringPipe.process(MonitoringPipe.java:142)
at com.sun.xml.ws.api.pipe.helper.PipeAdapter.processRequest(PipeAdapter.java:119)
at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:1136)
at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:1050)
at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:1019)
at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:877)
at com.sun.xml.ws.api.pipe.helper.AbstractTubeImpl.process(AbstractTubeImpl.java:136)
at com.sun.enterprise.security.webservices.CommonServerSecurityPipe.processRequest(CommonServerSecurityPipe.java:209)
at com.sun.enterprise.security.webservices.CommonServerSecurityPipe.process(CommonServerSecurityPipe.java:141)
at com.sun.xml.ws.api.pipe.helper.PipeAdapter.processRequest(PipeAdapter.java:119)
at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:1136)
at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:1050)
at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:1019)
at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:877)
at com.sun.xml.ws.server.WSEndpointImpl.process(WSEndpointImpl.java:419)
at com.sun.xml.ws.transport.http.HttpAdapter$HttpToolkit.handle(HttpAdapter.java:868)
at com.sun.xml.ws.transport.http.HttpAdapter.handle(HttpAdapter.java:422)
at com.sun.xml.ws.transport.http.servlet.ServletAdapter.handle(ServletAdapter.java:169)
at org.glassfish.webservices.JAXWSServlet.doPost(JAXWSServlet.java:169)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access0(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 14
at com.google.gson.stream.JsonReader.expect(JsonReader.java:339)
at com.google.gson.stream.JsonReader.beginObject(JsonReader.java:322)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:165)
... 66 more
请帮我解决一下。
提前致谢。
我的实体 bean 类是：
public class followup {
private String Active;
private String NextVisit;
private String CreateDate;
private String Designation;
private String ModifiedDate;
private String flag;
public String getActive() {
return Active;
}
public void setActive(String active) {
Active = active;
}
public String getNextVisit() {
return NextVisit;
}
public void setNextVisit(String nextVisit) {
NextVisit = nextVisit;
}
public String getCreateDate() {
return CreateDate;
}
public void setCreateDate(String createDate) {
CreateDate = createDate;
}
public String getDesignation() {
return Designation;
}
public void setDesignation(String designation) {
Designation = designation;
}
public String getModifiedDate() {
return ModifiedDate;
}
public void setModifiedDate(String modifiedDate) {
ModifiedDate = modifiedDate;
}
public String getFlag() {
return flag;
}
public void setFlag(String flag) {
this.flag = flag;
}
}
public class identity {
private String Active;
private String Createdate;
private String DistrictID;
private String HouseNo;
private String Code;
private String ModifiedDate;
private String flag;
public String getActive() {
return Active;
}
public void setActive(String active) {
Active = active;
}
public String getCreatedate() {
return Createdate;
}
public void setCreatedate(String createdate) {
Createdate = createdate;
}
public String getDistrictID() {
return DistrictID;
}
public void setDistrictID(String districtID) {
DistrictID = districtID;
}
public String getHouseNo() {
return HouseNo;
}
public void setHouseNo(String houseNo) {
HouseNo = houseNo;
}
public String getCode() {
return Code;
}
public void setCode(String code) {
Code = code;
}
public String getModifiedDate() {
return ModifiedDate;
}
public void setModifiedDate(String modifiedDate) {
ModifiedDate = modifiedDate;
}
public String getFlag() {
return flag;
}
public void setFlag(String flag) {
this.flag = flag;
}
}
{"followup":{ "Active" : 1,
"NextVisit" : "Yes",
"CreateDate" : "12/17/2014 02:53:43 PM",
"Designation" : "Yes",
"ModifiedDate" : "12/17/2014 02:53:43 PM",
"flag" : "I"
},
"identity":{ "Active" : 1,
"Createdate" : "12/17/2014 02:45:12 PM",
"DistrictID" : "01",
"HouseNo" : 3456,
"Code" : 22,
"ModifiedDate" : "12/17/2014 02:45:12 PM",
"flag" : "I"
}}
您还需要一个根实体来一次性解析 followup 和身份。
您的 Json 不正确，因为您必须创建两个对象和对象的属性，并且您创建了一个以数组作为参数的对象。
如果你想检查你的 JSon 去这个网站 Json online build
检查您是否在根上只有类型对象和 string:value 作为属性
{"followup":{ "Active" : 1,
"NextVisit" : "Yes",
"CreateDate" : "12/17/2014 02:53:43 PM",
"Designation" : "Yes",
"ModifiedDate" : "12/17/2014 02:53:43 PM",
"flag" : "I"
},
"identity":{ "Active" : 1,
"Createdate" : "12/17/2014 02:45:12 PM",
"DistrictID" : "01",
"HouseNo" : 3456,
"Code" : 22,
"ModifiedDate" : "12/17/2014 02:45:12 PM",
"flag" : "I"
}}
对于您的代码，您只需使用，假设 jsonString 与您看到的字符串相同：
Gson gson = new Gson();
identity hhIden =gson.fromJson(jsonString, identity .class);
followup ls=gson.fromJson(jsonString, followup .class);
我通过为每个对象创建反序列化器解决了这个问题，它将使用反序列化（final JsonElement json，final Type typeOfT，final JsonDeserializationContext context）方法来解析 JSON 字符串和 return 返回 Java 对象。
http://www.javacreed.com/gson-deserialiser-example/
谢谢大家,.....
我对将 JSON 字符串转换为不同的对象有疑问。
我的要求是我必须获取一个 JSON 字符串，然后我必须从该字符串中获取值并将其保存在 Postgresql 数据库中。
我的JSON字符串是
"followup":[{ "Active" : 1,
"NextVisit" : "Yes",
"CreateDate" : "12/17/2014 02:53:43 PM",
"Designation" : "Yes",
"ModifiedDate" : "12/17/2014 02:53:43 PM",
"flag" : "I"
},
"identity":[{ "Active" : 1,
"Createdate" : "12/17/2014 02:45:12 PM",
"DistrictID" : "01",
"HouseNo" : 3456,
"Code" : 22,
"ModifiedDate" : "12/17/2014 02:45:12 PM",
"flag" : "I"
}]
我制作了 2 个实体类，即 followup 和 identity，其变量与 Json String
中的变量相同我的代码是：
Gson gson = new Gson();
identity hhIden =gson.fromJson(jsonString, identity .class);
followup ls=gson.fromJson(jsonString, followup .class);
我在 netbeans 中遇到以下异常：
java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 14
com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 14
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:176)
at com.google.gson.Gson.fromJson(Gson.java:795)
at com.google.gson.Gson.fromJson(Gson.java:761)
at com.google.gson.Gson.fromJson(Gson.java:710)
at com.google.gson.Gson.fromJson(Gson.java:682)
at server.NewWebService.hello(NewWebService.java:59)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.glassfish.webservices.InstanceResolverImpl.invoke(InstanceResolverImpl.java:144)
at com.sun.xml.ws.server.InvokerTube.invoke(InvokerTube.java:149)
at com.sun.xml.ws.server.sei.SEIInvokerTube.processRequest(SEIInvokerTube.java:88)
at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:1136)
at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:1050)
at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:1019)
at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:877)
at com.sun.xml.ws.api.pipe.helper.AbstractTubeImpl.process(AbstractTubeImpl.java:136)
at org.glassfish.webservices.MonitoringPipe.process(MonitoringPipe.java:142)
at com.sun.xml.ws.api.pipe.helper.PipeAdapter.processRequest(PipeAdapter.java:119)
at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:1136)
at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:1050)
at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:1019)
at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:877)
at com.sun.xml.ws.api.pipe.helper.AbstractTubeImpl.process(AbstractTubeImpl.java:136)
at com.sun.enterprise.security.webservices.CommonServerSecurityPipe.processRequest(CommonServerSecurityPipe.java:209)
at com.sun.enterprise.security.webservices.CommonServerSecurityPipe.process(CommonServerSecurityPipe.java:141)
at com.sun.xml.ws.api.pipe.helper.PipeAdapter.processRequest(PipeAdapter.java:119)
at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:1136)
at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:1050)
at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:1019)
at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:877)
at com.sun.xml.ws.server.WSEndpointImpl.process(WSEndpointImpl.java:419)
at com.sun.xml.ws.transport.http.HttpAdapter$HttpToolkit.handle(HttpAdapter.java:868)
at com.sun.xml.ws.transport.http.HttpAdapter.handle(HttpAdapter.java:422)
at com.sun.xml.ws.transport.http.servlet.ServletAdapter.handle(ServletAdapter.java:169)
at org.glassfish.webservices.JAXWSServlet.doPost(JAXWSServlet.java:169)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access0(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 14
at com.google.gson.stream.JsonReader.expect(JsonReader.java:339)
at com.google.gson.stream.JsonReader.beginObject(JsonReader.java:322)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:165)
... 66 more
请帮我解决一下。 提前致谢。
我的实体 bean 类是：
public class followup {
private String Active;
private String NextVisit;
private String CreateDate;
private String Designation;
private String ModifiedDate;
private String flag;
public String getActive() {
return Active;
}
public void setActive(String active) {
Active = active;
}
public String getNextVisit() {
return NextVisit;
}
public void setNextVisit(String nextVisit) {
NextVisit = nextVisit;
}
public String getCreateDate() {
return CreateDate;
}
public void setCreateDate(String createDate) {
CreateDate = createDate;
}
public String getDesignation() {
return Designation;
}
public void setDesignation(String designation) {
Designation = designation;
}
public String getModifiedDate() {
return ModifiedDate;
}
public void setModifiedDate(String modifiedDate) {
ModifiedDate = modifiedDate;
}
public String getFlag() {
return flag;
}
public void setFlag(String flag) {
this.flag = flag;
}
}
public class identity {
private String Active;
private String Createdate;
private String DistrictID;
private String HouseNo;
private String Code;
private String ModifiedDate;
private String flag;
public String getActive() {
return Active;
}
public void setActive(String active) {
Active = active;
}
public String getCreatedate() {
return Createdate;
}
public void setCreatedate(String createdate) {
Createdate = createdate;
}
public String getDistrictID() {
return DistrictID;
}
public void setDistrictID(String districtID) {
DistrictID = districtID;
}
public String getHouseNo() {
return HouseNo;
}
public void setHouseNo(String houseNo) {
HouseNo = houseNo;
}
public String getCode() {
return Code;
}
public void setCode(String code) {
Code = code;
}
public String getModifiedDate() {
return ModifiedDate;
}
public void setModifiedDate(String modifiedDate) {
ModifiedDate = modifiedDate;
}
public String getFlag() {
return flag;
}
public void setFlag(String flag) {
this.flag = flag;
}
}
{"followup":{ "Active" : 1,
"NextVisit" : "Yes",
"CreateDate" : "12/17/2014 02:53:43 PM",
"Designation" : "Yes",
"ModifiedDate" : "12/17/2014 02:53:43 PM",
"flag" : "I"
},
"identity":{ "Active" : 1,
"Createdate" : "12/17/2014 02:45:12 PM",
"DistrictID" : "01",
"HouseNo" : 3456,
"Code" : 22,
"ModifiedDate" : "12/17/2014 02:45:12 PM",
"flag" : "I"
}}
您还需要一个根实体来一次性解析 followup 和身份。
您的 Json 不正确，因为您必须创建两个对象和对象的属性，并且您创建了一个以数组作为参数的对象。
如果你想检查你的 JSon 去这个网站 Json online build
检查您是否在根上只有类型对象和 string:value 作为属性
{"followup":{ "Active" : 1,
"NextVisit" : "Yes",
"CreateDate" : "12/17/2014 02:53:43 PM",
"Designation" : "Yes",
"ModifiedDate" : "12/17/2014 02:53:43 PM",
"flag" : "I"
},
"identity":{ "Active" : 1,
"Createdate" : "12/17/2014 02:45:12 PM",
"DistrictID" : "01",
"HouseNo" : 3456,
"Code" : 22,
"ModifiedDate" : "12/17/2014 02:45:12 PM",
"flag" : "I"
}}
对于您的代码，您只需使用，假设 jsonString 与您看到的字符串相同：
Gson gson = new Gson();
identity hhIden =gson.fromJson(jsonString, identity .class);
followup ls=gson.fromJson(jsonString, followup .class);
我通过为每个对象创建反序列化器解决了这个问题，它将使用反序列化（final JsonElement json，final Type typeOfT，final JsonDeserializationContext context）方法来解析 JSON 字符串和 return 返回 Java 对象。
http://www.javacreed.com/gson-deserialiser-example/
谢谢大家,.....