Intellij IDEA 2019 + Java Spring MVC + Hibernate學習筆記(1)

之前的技術棧一直是圍繞.net 做的，現在.net 技術棧的使用越來越少，越來越窄。好多原來的同事都轉Java開發了。

最近公司變動，自己需要重新找個坑，壓力山大。好多要求Java技術棧的根本沒機會進，自己的那點Java功底，之前做過混合開發的Java插件，Web項目10多年沒碰了...

好在幾個原來的同事都是所在公司的骨干，Java也用的很溜，嗯，向人家學習吧。。。

先把相關的家伙事准備好。

該安裝的安裝，該配置的配置。

開始架構第一個項目。點菜單File->New->Project。打開New Project窗口。左邊選Spring，右邊選擇Spring MVC。

拉到下邊選擇Hibernate和SQL Support,數據庫支持選擇MySQL

點擊下邊Next，給項目一個名字，JavaStudy。設置項目存放目錄。設置完成后點擊下邊的按鈕Finish。然后開始自動下載所依賴的相關包。

很快下載完成，第一個項目基本輪廓就有了。

選中web目錄下的index.jsp然后點擊菜單Run->run 'index.jsp'，開始第一次運行。。。

[2019-07-21 12:23:40,433] Artifact JavaStudy:war exploded: Artifact is being deployed, please wait...
21-Jul-2019 12:23:40.672 警告 [RMI TCP Connection(2)-127.0.0.1] org.apache.tomcat.util.descriptor.web.WebXml.setVersion Unknown version string [4.0]. Default version will be used.
21-Jul-2019 12:23:40.786 嚴重 [RMI TCP Connection(2)-127.0.0.1] org.apache.catalina.core.StandardContext.startInternal One or more listeners failed to start. Full details will be found in the appropriate container log file
21-Jul-2019 12:23:40.788 嚴重 [RMI TCP Connection(2)-127.0.0.1] org.apache.catalina.core.StandardContext.startInternal Context [/JavaStudy_war_exploded] startup failed due to previous errors
[2019-07-21 12:23:40,804] Artifact JavaStudy:war exploded: Error during artifact deployment. See server log for details.

第一次運行果然會掉進坑里...。各種搜索，然后做了下邊的操作。在web->WEB-INF目錄下新建一個classes目錄。然后建一個logging.properties文件。

logging.properties文件內容如下：

handlers = org.apache.juli.FileHandler, java.util.logging.ConsoleHandler    

############################################################
# Handler specific properties.
# Describes specific configuration info for Handlers.
############################################################

org.apache.juli.FileHandler.level = FINE    
org.apache.juli.FileHandler.directory = ../logs    
org.apache.juli.FileHandler.prefix = error-debug.    

java.util.logging.ConsoleHandler.level = FINE    
java.util.logging.ConsoleHandler.formatter = java.util.logging.SimpleFormatter

這樣運行后控制台就可以顯示具體的錯誤。否則只顯示出錯，不顯示具體內容，再次運行，

嚴重: Error configuring application listener of class [org.springframework.web.context.ContextLoaderListener]
java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1360)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1182)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:546)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:527)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:150)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4621)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5165)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:743)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:719)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:714)
    at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1720)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[2019-07-21 12:28:31,020] Artifact JavaStudy:war exploded: Error during artifact deployment. See server log for details.
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:287)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:483)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:432)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:287)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at com.sun.jmx.remote.security.MBeanServerAccessController.invoke(MBeanServerAccessController.java:468)
    at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468)
    at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76)
    at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1408)
    at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:357)
    at sun.rmi.transport.Transport$1.run(Transport.java:200)
    at sun.rmi.transport.Transport$1.run(Transport.java:197)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:573)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:834)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:688)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:687)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)

java.lang.ClassNotFoundException，這應該是沒有找到這個包。新創建的項目按道理說不應該啊。選中項目，然后按F4，打開Project Structure窗口。
在Project Settings找到了Artifacts中找到了一些問題提示。項目輸出結構貌似有問題。依賴包找不到

點擊下邊的Fix按鈕，選擇Add all missing 。。。

三個缺失的依賴庫被自動添加了

點擊OK，再次運行...，

瀏覽器打開了，這是要成功的節奏啊。期待hello world...

404是幾個意思？

又掉坑里了...

用IDEA+Tomcat + 404做關鍵字，搜索后找到了類似的問題，

Run->Edit Configuration,打開Run/Debug Configurations，選中Tomcate Server下的index.jsp，右邊選擇Deployment選項卡，然后把Application context 下的內容改成“/”,點擊按鈕OK

再次運行。。。

終於出來了

出現java.io.FileNotFoundException: C:\Program Files\Apache Software Foundation\Tomcat 8.5\bin\..\logs\error-debug.2019-07-25.log (拒絕訪問。)錯誤的時候是因為權限不足，無法寫入權限，用管理員身份運行Intellij IDEA即可。或者找到寫log的配置項，把log位置配置到有權限的位置也可以。