JavaEE-自定义SSM-编写核心
3.1 解决编写错误
3.1.1 注解
1）MySpringBootApplication
package com.czxy.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target(ElementType.TYPE) //只能修饰类
@Retention(RetentionPolicy.RUNTIME) //策略 运行时（内存）
public @interface MySpringBootApplication {
}
2）MyMapper
package com.czxy.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target(ElementType.TYPE) //只能修饰类
@Retention(RetentionPolicy.RUNTIME) //策略 运行时（内存）
public @interface MyMapper {
}
3）MySelect
package com.czxy.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target(ElementType.METHOD) //只能修饰方法
@Retention(RetentionPolicy.RUNTIME) //策略 运行时（内存）
public @interface MySelect {
public String value() ; //注解参数
}
4）MyService
package com.czxy.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target(ElementType.TYPE) //只能修饰类
@Retention(RetentionPolicy.RUNTIME) //策略 运行时（内存）
public @interface MyService {
}
5）MyRestController
package com.czxy.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target(ElementType.TYPE) //只能修饰类
@Retention(RetentionPolicy.RUNTIME) //策略 运行时（内存）
public @interface MyRestController {
}
6）MyRequestMapping
package com.czxy.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target(ElementType.TYPE) //只能修饰类
@Retention(RetentionPolicy.RUNTIME) //策略 运行时（内存）
public @interface MyRequestMapping {
public String value(); //参数
}
7）MyGetMapping
package com.czxy.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target(ElementType.METHOD) //只能修饰方法
@Retention(RetentionPolicy.RUNTIME) //策略 运行时（内存）
public @interface MyGetMapping {
// public String value() default "" ; //注解参数
}
8）MyPostMapping
package com.czxy.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target(ElementType.METHOD) //只能修饰方法
@Retention(RetentionPolicy.RUNTIME) //策略 运行时（内存）
public @interface MyPostMapping {
// public String value() default "" ; //注解参数
}
3.1.2 spring boot核心类
package com.czxy.boot;
import com.czxy.annotation.MySpringBootApplication;
public class MySpringApplication {
/**
* 整个程序的入口
* @param appClass
* @param args
*/
public static void run(Class appClass, String[] args) {
// 1）校验启动类是否有 @MySpringBootApplication注解
boolean hasBootApp = appClass.isAnnotationPresent(MySpringBootApplication.class);
if(!hasBootApp) {
throw new RuntimeException(appClass + "没有添加@MySpringBootApplication注解");
}
System.out.println("正常运行");
}
}
3.2 编写tomcat
3.2.1 测试
-
测试tomcat
package com.czxy; import org.apache.catalina.Context; import org.apache.catalina.LifecycleException; import org.apache.catalina.Wrapper; import org.apache.catalina.connector.Connector; import org.apache.catalina.core.StandardContext; import org.apache.catalina.loader.ParallelWebappClassLoader; import org.apache.catalina.loader.WebappLoader; import org.apache.catalina.startup.Tomcat; import org.apache.juli.logging.Log; import org.apache.juli.logging.LogFactory; import java.io.File; public class TestTomcat { public static void main(String[] args) throws LifecycleException { // https://blog.csdn.net/weixin_44061521/article/details/120262084 // 1. 创建tomcat Tomcat tomcat = new Tomcat(); // 2. 设置端口号 tomcat.setPort(8080); // 3. 设置tomcat的工作目录 tomcat.setBaseDir(new File("E:/workspaces_2021_quan12_5/mytomcat").getAbsolutePath()); // 4. 确定http请求使用的协议 Connector connector = new Connector("org.apache.coyote.http11.Http11NioProtocol"); connector.setThrowOnFailure(true); connector.setPort(8080); // 5. 使用的协议 与 tomcat 绑定 tomcat.getService().addConnector(connector); tomcat.setConnector(connector); tomcat.getHost().setAutoDeploy(false); // 6. 设置上下文 (固定) StandardContext context = new StandardContext(); context.setName(""); context.setDisplayName("application"); context.setPath(""); context.setDocBase("/"); context.addLifecycleListener(new Tomcat.FixContextListener()); context.setParentClassLoader(StandardContext.class.getClassLoader()); context.setCreateUploadTargets(true); // 7. web应用程序加载器（固定） WebappLoader loader = new WebappLoader(); loader.setLoaderClass(ParallelWebappClassLoader.class.getName()); loader.setDelegate(true); context.setLoader(loader); // 8. 设置默认Servlet addDefaultServlet(context); // 9. 将上下文对象设置给tomcat tomcat.getHost().addChild(context); // tomcat.addServlet("/", "dispatcherServlet", new MyDispacherServlet()); // 10. 启动tomcat tomcat.start(); } private static void addDefaultServlet(Context context) { Wrapper defaultServlet = context.createWrapper(); defaultServlet.setName("default"); // defaultServlet.setServletClass("org.apache.catalina.servlets.DefaultServlet"); defaultServlet.setServletClass("com.czxy.servlet.MyDispacherServlet"); defaultServlet.addInitParameter("debug", "0"); defaultServlet.addInitParameter("listings", "false"); defaultServlet.setLoadOnStartup(1); // Otherwise the default location of a Spring DispatcherServlet cannot be set defaultServlet.setOverridable(true); context.addChild(defaultServlet); context.addServletMappingDecoded("/", "default"); } } -
自定义前端控制器
package com.czxy.servlet; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; public class MyDispatcherServlet extends HttpServlet { @Override public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { System.out.println("哈哈，我执行了！"); //返回数据 response.getWriter().print("6666"); } } -
创建文件件
浏览器测试
3.2.2 自定义web服务
-
创建web服务器（再target目录下创建tomcat需要的目录结构
target/mytomcat/webapps）- 注意：自定义web服务，需修改一个bug，端口号port从yml文件中读取。
package com.czxy.server; import com.czxy.servlet.MyDispatcherServlet; import org.apache.catalina.Context; import org.apache.catalina.LifecycleException; import org.apache.catalina.Wrapper; import org.apache.catalina.connector.Connector; import org.apache.catalina.core.StandardContext; import org.apache.catalina.loader.ParallelWebappClassLoader; import org.apache.catalina.loader.WebappLoader; import org.apache.catalina.startup.Tomcat; import java.io.File; import java.io.IOException; public class MyWebServer { //tomcat路径 private File tomcatDir; private void init() { try { //1 获得target目录 String classPath = MyWebServer.class.getClassLoader().getResource("").getPath(); File target = new File(classPath,"../"); //2 tomcat目录 tomcatDir = new File(target, "mytomcat"); if(!tomcatDir.exists()) { tomcatDir.mkdirs(); } //3 web程序目录 File webAppDir = new File(tomcatDir, "webapps"); if(!webAppDir.exists()) { webAppDir.mkdirs(); } } catch (Exception e) { throw new RuntimeException(e); } } public void start() { // 初始化操作，准备tomcat目录 init(); //创建tomcat实例 try { Tomcat tomcat = new Tomcat(); //获得设置的端口号，如果没有，默认8080 Integer port = 8080; tomcat.setPort(port); //设置工作目录 tomcat.setBaseDir(tomcatDir.getAbsolutePath()); Connector connector = new Connector("org.apache.coyote.http11.Http11NioProtocol"); connector.setThrowOnFailure(true); connector.setPort(port); tomcat.getService().addConnector(connector); tomcat.setConnector(connector); tomcat.getHost().setAutoDeploy(false); //设置上下文 StandardContext context = new StandardContext(); context.setName(""); context.setDisplayName("application"); context.setPath(""); context.setDocBase("/"); context.addLifecycleListener(new Tomcat.FixContextListener()); context.setParentClassLoader(StandardContext.class.getClassLoader()); context.setCreateUploadTargets(true); //web程序加载器 WebappLoader loader = new WebappLoader(); loader.setLoaderClass(ParallelWebappClassLoader.class.getName()); loader.setDelegate(true); context.setLoader(loader); //设置默认，直接整合spring mvc（DispatcherServlet） addDefaultServlet(context); tomcat.getHost().addChild(context); tomcat.start(); } catch (LifecycleException e) { throw new RuntimeException(e); } } private static void addDefaultServlet(Context context) { Wrapper defaultServlet = context.createWrapper(); defaultServlet.setName("default"); // defaultServlet.setServletClass("org.apache.catalina.servlets.DefaultServlet"); defaultServlet.setServletClass(MyDispatcherServlet.class.getName()); defaultServlet.addInitParameter("debug", "0"); defaultServlet.addInitParameter("listings", "false"); defaultServlet.setLoadOnStartup(1); // Otherwise the default location of a Spring DispatcherServlet cannot be set defaultServlet.setOverridable(true); context.addChild(defaultServlet); context.addServletMappingDecoded("/", "default"); } } -
调用web服务（启动tomcat）
package com.czxy.boot;
import com.czxy.annotation.MySpringBootApplication;
import com.czxy.server.MyWebServer;
public class MySpringApplication {
/**
* 整个程序的入口
* @param appClass
* @param args
*/
public static void run(Class appClass, String[] args) {
// 1）校验启动类是否有 @MySpringBootApplication注解
boolean hasBootApp = appClass.isAnnotationPresent(MySpringBootApplication.class);
if(!hasBootApp) {
throw new RuntimeException(appClass + "没有添加@MySpringBootApplication注解");
}
System.out.println("正常运行");
// 3）启动web服务
MyWebServer myWebServer = new MyWebServer();
myWebServer.start();
}
}