restful-java私有vs公共
这是一段正常工作的代码。但当第三行和第四行变为公共行时restful-java私有vs公共,java,rest,Java,Rest,这是一段正常工作的代码。但当第三行和第四行变为公共行时 @XmlRootElement public class Activity { private String description; private int duration; public String getDescription() { return description; } public void setDescription(String description) {
@XmlRootElement
public class Activity {
private String description;
private int duration;
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public int getDuration() {
return duration;
}
public void setDuration(int duration) {
this.duration = duration;
}
我得到错误500。我不明白
public
成员类型有什么问题。每个对象都可以访问public
成员类型。还请解释何时使用public
或private
?错误500不是真正的错误。查看日志,您可能会看到真正的错误
以下是一个(最小、完整且可验证的示例):
运行它会出现以下错误:
import javax.xml.bind.JAXBContext;
import javax.xml.bind.annotation.XmlRootElement;
public class Test {
public static void main(String[] args) throws Exception {
JAXBContext.newInstance(Activity.class);
}
}
@XmlRootElement
class Activity {
public String description;
public int duration;
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public int getDuration() {
return duration;
}
public void setDuration(int duration) {
this.duration = duration;
}
}
线程“main”com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException中的异常:2次illegalannotationException计数
类有两个同名的属性“description”
此问题与以下位置有关:
在public java.lang.String Activity.getDescription()中
活跃
此问题与以下位置有关:
在public java.lang.String Activity.description
活跃
类有两个同名的属性“duration”
此问题与以下位置有关:
在public int Activity.getDuration()中
活跃
此问题与以下位置有关:
在公共int活动中。持续时间
活跃
位于com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException$Builder.check(IllegalAnnotationsException.java:91)
位于com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.getTypeInfoSet(JAXBContextImpl.java:445)
位于com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.(JAXBContextImpl.java:277)
位于com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.(JAXBContextImpl.java:124)
位于com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl$JAXBContextBuilder.build(JAXBContextImpl.java:1123)
位于com.sun.xml.internal.bind.v2.ContextFactory.createContext(ContextFactory.java:147)
在sun.reflect.NativeMethodAccessorImpl.invoke0(本机方法)处
位于sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
在sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)中
位于java.lang.reflect.Method.invoke(Method.java:498)
位于javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:247)
位于javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:234)
位于javax.xml.bind.ContextFinder.find(ContextFinder.java:462)
位于javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:641)
位于javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:584)
at Test.main(Test.java:7)
如您所见,将字段设置为public
意味着JAXB看到两个同名属性,一个由public
字段定义,另一个由get
/set
bean方法定义
由于如果将字段设置为公共的
,则使用getter和setter方法没有任何意义,因此如果希望字段为公共的
,请删除这些方法
我建议不要把它们公开。你为什么要这么做?当您有用于访问字段的getter和setter方法时,就不需要了。如果您将字段公开,使用getter和setter方法有什么意义?当您将其公开时,系统会看到两个同名的值:字段和属性(get/set)。删除get/set方法,或保持字段私有。
import javax.xml.bind.JAXBContext;
import javax.xml.bind.annotation.XmlRootElement;
public class Test {
public static void main(String[] args) throws Exception {
JAXBContext.newInstance(Activity.class);
}
}
@XmlRootElement
class Activity {
public String description;
public int duration;
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public int getDuration() {
return duration;
}
public void setDuration(int duration) {
this.duration = duration;
}
}
Exception in thread "main" com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException: 2 counts of IllegalAnnotationExceptions
Class has two properties of the same name "description"
this problem is related to the following location:
at public java.lang.String Activity.getDescription()
at Activity
this problem is related to the following location:
at public java.lang.String Activity.description
at Activity
Class has two properties of the same name "duration"
this problem is related to the following location:
at public int Activity.getDuration()
at Activity
this problem is related to the following location:
at public int Activity.duration
at Activity
at com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException$Builder.check(IllegalAnnotationsException.java:91)
at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.getTypeInfoSet(JAXBContextImpl.java:445)
at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.<init>(JAXBContextImpl.java:277)
at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.<init>(JAXBContextImpl.java:124)
at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl$JAXBContextBuilder.build(JAXBContextImpl.java:1123)
at com.sun.xml.internal.bind.v2.ContextFactory.createContext(ContextFactory.java:147)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:247)
at javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:234)
at javax.xml.bind.ContextFinder.find(ContextFinder.java:462)
at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:641)
at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:584)
at Test.main(Test.java:7)