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我發佈a question last night關於Java反射,我發現編譯器警告今天上午。檢查Java反射調用的正確方法?
C:\javasandbox\reflection>javac ReflectionTest.java
Note: ReflectionTest.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
C:\javasandbox\reflection>javac -Xlint:unchecked ReflectionTest.java
ReflectionTest.java:17: warning: [unchecked] unchecked call to
getDeclaredMethod(java.lang.String,java.lang.Class<?>...) as a member of the raw
type java.lang.Class
myMethod = myTarget.getDeclaredMethod("getValue");
^
ReflectionTest.java:22: warning: [unchecked] unchecked call to
getDeclaredMethod(java.lang.String,java.lang.Class<?>...) as a member of the raw
type java.lang.Class
myMethod = myTarget.getDeclaredMethod("setValue", params);
^
2 warnings
是否有「適當的」方式來檢查這些返回的方法? (即是否有擺脫這些警告的正確方法是什麼?)
的源代碼:
import java.lang.reflect.*;
class Target {
String value;
public Target() { this.value = new String("."); }
public void setValue(String value) { this.value = value; }
public String getValue() { return this.value; }
}
class ReflectionTest {
public static void main(String args[]) {
try {
Class myTarget = Class.forName("Target");
Method myMethod;
myMethod = myTarget.getDeclaredMethod("getValue");
System.out.println("Method Name: " + myMethod.toString());
Class params[] = new Class[1];
params[0] = String.class;
myMethod = myTarget.getDeclaredMethod("setValue", params);
System.out.println("Method Name: " + myMethod.toString());
} catch (Exception e) {
System.out.println("ERROR");
}
}
}
我相信當前的JDK7編譯器會在該行上提供rawtypes警告,以及使用變量的延遲未檢查警告。 – 2009-05-21 12:55:24