Java Netbeans中的StdIn库-StdIn.readInt（）

我只是一个java初学者，目前正在大学学习，但由于一些原因，我不想进入大学，我不能问我的导师

我在Netbeans中使用StdIn库时遇到问题。在课堂上，我们使用DrJava，但由于我无法让它在我的Mac上运行，所以我求助于Netbeans。在下面的代码中，我可以让它在DrJava中运行（这是使用标准输入和输出的基本介绍），但是当我在netbeans中运行它时，它会抛出一个运行时错误

（我已将StdIn.java和StdOut.java文件包括在与MaxMin.java文件相同的目录中）

我很抱歉这一定是一个非常基本的问题，但我在堆栈溢出中找不到任何相关的帮助

我确信代码本身是正确的，因为它完全是从在线教科书中复制的：

有人能解释一下为什么Netbeans抛出运行时错误而不是请求我输入吗

编辑 作为对建议的回应，我在项目构建选项中取消了“保存时编译”，然后执行了“清理并构建项目”。并得出以下错误：

ant -f /Users/xUsernamex/NetBeansProjects/MaxMin -Dnb.internal.action.name=rebuild clean jar
init:
deps-clean:
Updating property file: /Users/xUsernamex/NetBeansProjects/MaxMin/build/built-clean.properties
Deleting directory /Users/xUsernamex/NetBeansProjects/MaxMin/build
clean:
init:
deps-jar:
Created dir: /Users/xUsernamex/NetBeansProjects/MaxMin/build
Updating property file: /Users/xUsernamex/NetBeansProjects/MaxMin/build/built-jar.properties
Created dir: /Users/xUsernamex/NetBeansProjects/MaxMin/build/classes
Created dir: /Users/xUsernamex/NetBeansProjects/MaxMin/build/empty
Created dir: /Users/xUsernamex/NetBeansProjects/MaxMin/build/generated-sources/ap-source-output
Compiling 3 source files to /Users/xUsernamex/NetBeansProjects/MaxMin/build/classes
/Users/xUsernamex/NetBeansProjects/MaxMin/src/maxmin/MaxMin.java:19: error: cannot find symbol
    int max = StdIn.readInt();
  symbol:   variable StdIn
  location: class MaxMin
/Users/xUsernamex/NetBeansProjects/MaxMin/src/maxmin/MaxMin.java:23: error: cannot find symbol
    while (!StdIn.isEmpty()) {
  symbol:   variable StdIn
  location: class MaxMin
/Users/xUsernamex/NetBeansProjects/MaxMin/src/maxmin/MaxMin.java:24: error: cannot find symbol
        int value = StdIn.readInt();
  symbol:   variable StdIn
  location: class MaxMin
/Users/xUsernamex/NetBeansProjects/MaxMin/src/maxmin/MaxMin.java:31: error: cannot find symbol
            if (value < 0) StdOut.println("Please use positive values");
  symbol:   variable StdOut
  location: class MaxMin
/Users/xUsernamex/NetBeansProjects/MaxMin/src/maxmin/MaxMin.java:35: error: cannot find symbol
    StdOut.println("maximum  = " + max + ", minimum = " + min);
  symbol:   variable StdOut
  location: class MaxMin
5 errors
/Users/xUsernamex/NetBeansProjects/MaxMin/nbproject/build-impl.xml:923: The following error         occurred while executing this line:
/Users/xUsernamex/NetBeansProjects/MaxMin/nbproject/build-impl.xml:263: Compile failed; see the     compiler error output for details.
BUILD FAILED (total time: 0 seconds)

ant-f/Users/xUsernamex/NetBeansProjects/MaxMin-Dnb.internal.action.name=rebuild clean jar
初始化：
清洁署署长：
正在更新属性文件：/Users/xUsernamex/NetBeansProjects/MaxMin/build/build-clean.properties
正在删除目录/Users/xUsernamex/NetBeansProjects/MaxMin/build
清洁：
初始化：
deps jar：
创建目录：/Users/xUsernamex/NetBeansProjects/MaxMin/build
正在更新属性文件：/Users/xUsernamex/NetBeansProjects/MaxMin/build/build-jar.properties
创建目录：/Users/xUsernamex/NetBeansProjects/MaxMin/build/classes
创建目录：/Users/xUsernamex/NetBeansProjects/MaxMin/build/empty
创建目录：/Users/xUsernamex/NetBeansProjects/MaxMin/build/generated sources/ap source output
将3个源文件编译为/Users/xUsernamex/NetBeansProjects/MaxMin/build/classes
/Users/xUsernamex/NetBeansProjects/MaxMin/src/MaxMin/MaxMin.java:19:错误：找不到符号
int max=StdIn.readInt（）；
符号：变量StdIn
位置：MaxMin类
/Users/xUsernamex/NetBeansProjects/MaxMin/src/MaxMin/MaxMin.java:23:错误：找不到符号
而（！StdIn.isEmpty（））{
符号：变量StdIn
位置：MaxMin类
/Users/xUsernamex/NetBeansProjects/MaxMin/src/MaxMin/MaxMin.java:24:错误：找不到符号
int value=StdIn.readInt（）；
符号：变量StdIn
位置：MaxMin类
/Users/xUsernamex/NetBeansProjects/MaxMin/src/MaxMin/MaxMin.java:31:错误：找不到符号
如果（值<0）标准输出打印项次（“请使用正值”）；
符号：变量StdOut
位置：MaxMin类
/Users/xUsernamex/NetBeansProjects/MaxMin/src/MaxMin/MaxMin.java:35:错误：找不到符号
StdOut.println（“最大值=“+max+”，最小值=“+min”）；
符号：变量StdOut
位置：MaxMin类
5个错误
/Users/xUsernamex/NetBeansProjects/MaxMin/nbproject/build impl.xml:923:执行此行时发生以下错误：
/Users/xUsernamex/NetBeansProjects/MaxMin/nbproject/build impl.xml:263:Compile失败；有关详细信息，请参阅编译器错误输出。
生成失败（总时间：0秒）

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在我看来，似乎我在识别StdIn和StdOut库方面遇到了一些问题，但我不确定该怎么办。在Netbeans中，我应该将它们放在哪个文件夹中？

如果某些类不可编译，则在Netbeans中会发生此错误。您可以尝试在项目构建选项中取消选择“保存时编译”。现在清理并构建您的p项目，然后运行您的代码。

我已经尝试了您的建议，现在有进一步的问题，有什么建议吗？

    Exception in thread "main" java.lang.RuntimeException: Uncompilable source code - Erroneous sym type: maxmin.StdIn.readInt
at maxmin.MaxMin.main(MaxMin.java:19)
    Java Result: 1
    BUILD SUCCESSFUL (total time: 0 seconds)

ant -f /Users/xUsernamex/NetBeansProjects/MaxMin -Dnb.internal.action.name=rebuild clean jar
init:
deps-clean:
Updating property file: /Users/xUsernamex/NetBeansProjects/MaxMin/build/built-clean.properties
Deleting directory /Users/xUsernamex/NetBeansProjects/MaxMin/build
clean:
init:
deps-jar:
Created dir: /Users/xUsernamex/NetBeansProjects/MaxMin/build
Updating property file: /Users/xUsernamex/NetBeansProjects/MaxMin/build/built-jar.properties
Created dir: /Users/xUsernamex/NetBeansProjects/MaxMin/build/classes
Created dir: /Users/xUsernamex/NetBeansProjects/MaxMin/build/empty
Created dir: /Users/xUsernamex/NetBeansProjects/MaxMin/build/generated-sources/ap-source-output
Compiling 3 source files to /Users/xUsernamex/NetBeansProjects/MaxMin/build/classes
/Users/xUsernamex/NetBeansProjects/MaxMin/src/maxmin/MaxMin.java:19: error: cannot find symbol
    int max = StdIn.readInt();
  symbol:   variable StdIn
  location: class MaxMin
/Users/xUsernamex/NetBeansProjects/MaxMin/src/maxmin/MaxMin.java:23: error: cannot find symbol
    while (!StdIn.isEmpty()) {
  symbol:   variable StdIn
  location: class MaxMin
/Users/xUsernamex/NetBeansProjects/MaxMin/src/maxmin/MaxMin.java:24: error: cannot find symbol
        int value = StdIn.readInt();
  symbol:   variable StdIn
  location: class MaxMin
/Users/xUsernamex/NetBeansProjects/MaxMin/src/maxmin/MaxMin.java:31: error: cannot find symbol
            if (value < 0) StdOut.println("Please use positive values");
  symbol:   variable StdOut
  location: class MaxMin
/Users/xUsernamex/NetBeansProjects/MaxMin/src/maxmin/MaxMin.java:35: error: cannot find symbol
    StdOut.println("maximum  = " + max + ", minimum = " + min);
  symbol:   variable StdOut
  location: class MaxMin
5 errors
/Users/xUsernamex/NetBeansProjects/MaxMin/nbproject/build-impl.xml:923: The following error         occurred while executing this line:
/Users/xUsernamex/NetBeansProjects/MaxMin/nbproject/build-impl.xml:263: Compile failed; see the     compiler error output for details.
BUILD FAILED (total time: 0 seconds)