#IDEA 小技巧

  • alt按住移动鼠标可以多行编辑。
  • cmd + n可以快速创建构造器（自行选择参数）或者重写继承方法。

#从流中获取 properties

新建了一个Maven Module，从archetype中创建的。

Maven Module截图

#创建 properties 文件

文件路径为：servlet-02/src/main/resources/

文件名：db.properties

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username=root
password=123456

#创建 class

文件路径为：servlet-02/src/main/java/

包名为：xyz.onns.servlet

文件名：TestResourceStream.java

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package xyz.onns.servlet;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Properties;

public class TestResourceStream extends HttpServlet {
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		InputStream resourceAsStream = this.getServletContext().getResourceAsStream("/WEB-INF/classes/db.properties");
		Properties properties = new Properties();
		properties.load(resourceAsStream);
		String username = properties.getProperty("username");
		String password = properties.getProperty("password");
		String maybenull = properties.getProperty("maybenull");
		System.out.println("TestResourceStream");
		resp.setHeader("Content-Type", "text/html;charset=utf-8");

		PrintWriter writer = resp.getWriter();
		writer.print("Success!成功了！");
		writer.print("<br/>");
		writer.print(username);
		writer.print(password);
		writer.print(maybenull);
	}

	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		doGet(req, resp);
	}
}

#创建路由

文件路径为：servlet-02/src/main/webapp/WEB-INF/

文件名：web.xml

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<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
                      http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0"
         metadata-complete="true">

    <servlet>
        <servlet-name>TestResourceStream</servlet-name>
        <servlet-class>xyz.onns.servlet.TestResourceStream</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>TestResourceStream</servlet-name>
        <url-pattern>/testr</url-pattern>
    </servlet-mapping>

</web-app>

#小结

如果先写这句话：

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PrintWriter writer = resp.getWriter();

再写这句话：

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resp.setHeader("Content-Type", "text/html;charset=utf-8");

在处理中文的时候也还是会乱码，大概在创建PrintWriter对象的时候就已经把相关参数传过去了吧。

#相关链接