Question

我正在尝试编译要在webapp中使用的源代码。我知道Ubuntu中的内容与Windows中的内容不同，永久设置classpath并不是一件好事，所以我决定暂时设置标志。这是我在终端的命令：

littlejavachild@ubuntu:~/LittleJavaChild/ServletProjects/beerV1$ javac -cp "/usr/share/tomcat7/servlet-api.jar" -d classes src/com/example/*.java

我想要达到的目的是：

编译包.java

中的所有com.example个文件

将.class文件直接发送到相应的目录

将classes文件夹复制到WEB-INF文件夹

尽管设置classpath我收到了错误：

src/com/example/ListenerTester.java:3: error: package javax.servlet does not exist
import javax.servlet.*;
^
src/com/example/ListenerTester.java:4: error: package javax.servlet.http does not exist
import javax.servlet.http.*;
^
src/com/example/ListenerTester.java:7: error: cannot find symbol
public class ListenerTester extends HttpServlet{
                                    ^
  symbol: class HttpServlet
src/com/example/ListenerTester.java:8: error: cannot find symbol
    public void doGet(HttpServletRequest request,
                      ^
  symbol:   class HttpServletRequest
  location: class ListenerTester
src/com/example/ListenerTester.java:9: error: cannot find symbol
                HttpServletResponse response) throws IOException, ServletException {
                ^
  symbol:   class HttpServletResponse
  location: class ListenerTester
src/com/example/ListenerTester.java:9: error: cannot find symbol
                HttpServletResponse response) throws IOException, ServletException {
                                                                  ^
  symbol:   class ServletException
  location: class ListenerTester
src/com/example/MyServletContextListener.java:2: error: package javax.servlet does not exist
import javax.servlet.*;
^
src/com/example/MyServletContextListener.java:4: error: cannot find symbol
public class MyServletContextListener implements ServletContextListener{
                                                 ^
  symbol: class ServletContextListener
src/com/example/MyServletContextListener.java:5: error: cannot find symbol
    public void contextInitialized(ServletContextEvent event){
                                   ^
  symbol:   class ServletContextEvent
  location: class MyServletContextListener
src/com/example/MyServletContextListener.java:12: error: cannot find symbol
    public void contextDestroyed(ServletContextEvent event){
                                 ^
  symbol:   class ServletContextEvent
  location: class MyServletContextListener
src/com/example/ListenerTester.java:14: error: cannot find symbol
        Dog dog = (Dog) getServletContext().getAttribute("dog");
                        ^
  symbol:   method getServletContext()
  location: class ListenerTester
src/com/example/MyServletContextListener.java:6: error: cannot find symbol
        ServletContext sc = event.getServletContext();
        ^
  symbol:   class ServletContext
  location: class MyServletContextListener

我知道当类路径设置不正确时会发生这些错误。请帮我解决一下这个。告诉我出了什么问题，我该如何纠正它以及将来如何避免它。

使用-verbose更新

[类文件的搜索路径：/usr/lib/jvm/java-7-openjdk-i386/jre/lib/resources.jar,/usr/lib/jvm/java-7-openjdk-i386/jre/ LIB / rt.jar中，/ usr / lib中/ JVM / JAVA -7-的openjdk-I386 / JRE / LIB / sunrsasign.jar，/ usr / lib中/ JVM / JAVA -7-的openjdk-I386 / JRE / LIB / JSSE。罐子，/ usr / lib中/ JVM / JAVA -7-的openjdk-I386 / JRE / LIB / jce.jar，/ usr / lib中/ JVM / JAVA -7-的openjdk-I386 / JRE / LIB / charsets.jar，在/ usr /lib/jvm/java-7-openjdk-i386/jre/lib/netx.jar,/usr/lib/jvm/java-7-openjdk-i386/jre/lib/plugin.jar,/usr/lib/jvm /java-7-openjdk-i386/jre/lib/rhino.jar,/usr/lib/jvm/java-7-openjdk-i386/jre/lib/jfr.jar,/usr/lib/jvm/java-7 -openjdk-I386 / JRE /类，/ usr / lib中/ JVM / JAVA -7-的openjdk-I386 / JRE / lib / ext目录/ localedata.jar，/ usr / lib中/ JVM / JAVA -7-的openjdk-I386 / JRE /lib/ext/sunjce_provider.jar,/usr/lib/jvm/java-7-openjdk-i386/jre/lib/ext/dnsns.jar,/usr/lib/jvm/java-7-openjdk-i386/jre /lib/ext/java-atk-wrapper.jar,/usr/lib/jvm/java-7-openjdk-i386/jre/lib/ext/pulse-java.jar,/usr/lib/jvm/java-7 -openjdk-I386 / JRE / lib / ext目录/ sunpkcs11.jar，/ usr / lib中/ JVM / JAVA -7-的openjdk-I386 / JRE / LIB / EX吨/ zipfs.jar。是/ usr /共享/ tomcat7 / servlet的api.jar文件]

Answer 1

将任务分成几位，让我们先尝试编译java文件。稍后检查如何移动类文件。

错误确实表明它没有找到所需的类，因此jar没有正确添加到类路径中。检查一下

javac -classpath .:/usr/share/tomcat7/servlet-api.jar src/com/example/*.java

确保罐子出现在给定位置。还可以尝试从src文件夹运行它，并将路径指定为com / example / * .java

Answer 2

我会尝试使用-classpath而不是-cp。 Ubuntu man page for javac未指明-cp选项。您还可以添加-verbose以获得javac的更多输出。

注意：我的mac上的javac实现不同意，但我不在ubuntu机器上。

在Ubuntu中编译Servlet会返回错误

使用-verbose更新

2 个答案: