cannot resolve symbol怎么处理???

[luoxiang2000]

源代码如下：
package firstPackage;
import java.lang.system;
import java.io.*;

public class Hello{
public String personName;
public void Hello(){};
public String readname() {
int ch;
String name = "";
boolean ok = false;
System.out.println("Please enter your name:");
while (!ok) {
try {
ch = System.in.read();
if (ch<0 || (char)ch == '\n')
ok = true;
else if ((char)ch != '\r')
name = name + (char)ch;
}
catch (IOException e) {
ok = true;
}
}
personName = name;
return name;
}
public static void main (String[] args) {
String name;
Hello myfirst = new Hello();
name = myfirst.readname();
System.out.println("Welcome to the Java World." + name + ".");
System.out.println("And may you success.");
}
}

报错：
Hello.java:2:cannot resolve symbol
symbol:class system
location:package land
import java.lang.system;

[luoxiang2000]

编译成功了，可是运行还是有错误：
Exception in thread "main" java.lang.NoClassDefFoundError:Hello<wrong name:firstPackage/Hello>

[luoxiang2000]

一个Hello程序都这么难吗？哎！
package firstPackage到底是什么意思？
大虾们，帮帮忙！谢了！

[geyf]

运行时，
这样用;
java firstPackage.Hello

[luoxiang2000]

还是不行呀！？？？

[徐蕴]

退到firstpackage的父目录
执行java -cp . firstPackage.Hello

[cowboy1114]

java.lang.System中的System的第一个s应该大写，程序修改成如下,：

import java.lang.System;
import java.io.*;

public class Hello{
public String personName;
public void Hello(){};
public String readname() {
int ch;
String name = "";
boolean ok = false;
System.out.println("Please enter your name:");
while (!ok) {
try {
ch = System.in.read();
if (ch<0 || (char)ch == '\n')
ok = true;
else if ((char)ch != '\r')
name = name + (char)ch;
}
catch (IOException e) {
ok = true;
}
}
personName = name;
return name;
}
public static void main (String[] args) {
String name;
Hello myfirst = new Hello();
name = myfirst.readname();
System.out.println("Welcome to the Java World." + name + ".");
System.out.println("And may you success.");
}
}

[网络咖啡]

system改成System

[luoxiang2000]

报错信息：
Exception in thread "main" java.lang.NoClassDefFoundError: Hello (wrong name: fi
rstPackage/Hello)
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:509)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:12
3)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:246)
at java.net.URLClassLoader.access$100(URLClassLoader.java:54)
at java.net.URLClassLoader$1.run(URLClassLoader.java:193)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:186)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:265)
at java.lang.ClassLoader.loadClass(ClassLoader.java:262)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:322)

[geyf]

看看目录结构，
需要在firstPackage目录的同级执行
firstPackage.Hello

[徐蕴]

折腾了好久
发现还是大小写的问题：（
或者把你的那个目录名字改成firstPackage注意P大写
或者把你程序中的package firstPackage改成小写