找不到符号：java.net.Socket

在处理更大的项目时，使用java.net.Socket的几行代码未能编译。这是在Mac 10.5.8上，带有Java for Mac OS X 10.5更新4（

Java版本“1.5.0\u 20”

）。其他东西（awt、ssl工厂、踏板等）仍在编译和运行。我把有问题的代码拉到一个小类中

false.java

：

import java.net.Socket;
public class Fake {
  public String sendMsg() {
    Socket so;
    try {      
      so = Socket("www.yahoo.com", 80);
    } catch (Exception e) {
    } finally {
    }
    return "";      
  }
}

如果我用

javac-verbose-Fake.java

编译它，它将从jar文件加载Socket.class，但随后报告

Fake.java:6:找不到符号

。类路径似乎都是正确的，所以我不确定什么是令人不快的问题。完整的编译输出是：

$ javac -verbose Fake.java 
[parsing started Fake.java]
[parsing completed 41ms]
[search path for source files: [.]]
[search path for class files: [/System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/classes.jar, /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/ui.jar, /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/laf.jar, /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/jsse.jar, /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/jce.jar, /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/charsets.jar, /Users/shamma/Library/Java/Extensions/js.jar, /System/Library/Java/Extensions/AppleScriptEngine.jar, /System/Library/Java/Extensions/CoreAudio.jar, /System/Library/Java/Extensions/dns_sd.jar, /System/Library/Java/Extensions/j3daudio.jar, /System/Library/Java/Extensions/j3dcore.jar, /System/Library/Java/Extensions/j3dutils.jar, /System/Library/Java/Extensions/jai_codec.jar, /System/Library/Java/Extensions/jai_core.jar, /System/Library/Java/Extensions/mlibwrapper_jai.jar, /System/Library/Java/Extensions/MRJToolkit.jar, /System/Library/Java/Extensions/QTJava.zip, /System/Library/Java/Extensions/vecmath.jar, /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Home/lib/ext/apple_provider.jar, /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Home/lib/ext/dnsns.jar, /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Home/lib/ext/localedata.jar, /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Home/lib/ext/sunjce_provider.jar, /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Home/lib/ext/sunpkcs11.jar, .]]
[loading /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/classes.jar(java/net/Socket.class)]
[loading /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/classes.jar(java/lang/Object.class)]
[loading /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/classes.jar(java/lang/String.class)]
[checking Fake]
Fake.java:6: cannot find symbol
symbol  : method Socket(java.lang.String,int)
location: class Fake
      so = Socket("www.yahoo.com", 80);
           ^
[loading /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/classes.jar(java/lang/Exception.class)]
[loading /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Classes/classes.jar(java/lang/Throwable.class)]
[total 282ms]
1 error

奇怪的是，它在

false

类中查找

Socket（）

方法。如果我将第6行编辑为：

so = java.net.Socket("www.yahoo.com", 80);

错误变为：

Fake.java:6: cannot find symbol
symbol  : class net
location: package java
      so = java.net.Socket("www.yahoo.com", 80);
               ^
1 error

---

这完全是瞎猜，但是你应该在输入之前加上new关键字吗

so = Socket("www.yahoo.com", 80);

应该是

so = new Socket("www.yahoo.com", 80);

---

这完全是瞎猜，但是你应该在输入之前加上new关键字吗

so = Socket("www.yahoo.com", 80);

应该是

so = new Socket("www.yahoo.com", 80);

应该是：

so = new Socket(...)

应该是：

so = new Socket(...)

应该是

so = new Socket("www.yahoo.com", 80);

你好，简

应该是

so = new Socket("www.yahoo.com", 80);

---

你好，Jan

等等，你是说他没有试图调用命名空间

java

中类

net

中的方法

Socket

？当然，这个类是不存在的……哦，我试图把它静态地称为工厂。等等，你是说他没有试图调用命名空间

java

中类

net

中的方法

Socket

？当然，那个类是不存在的……哦，我试着把它静态地称为工厂。