java读取Properties文件的方法

resource.properties的内容：

com.tsinkai.ettp.name=imooc
com.tsinkai.ettp.website=www.imooc.com
com.tsinkai.ettp.language=java

1、使用java.util.Properties的load(InputStream inStream)方法。

先读取文件生成inputStream流，再用load加载。

    @Test
    public void testReadProperties3() throws IOException {
        Properties properties = new Properties();
//        InputStream inputStream = this.getClass().getResourceAsStream("/resource.properties");
//        InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream("resource.properties");
        Resource resource = new ClassPathResource("resource.properties");
        InputStream inputStream = resource.getInputStream();

        properties.load(inputStream);
        System.out.println(properties.getProperty("com.tsinkai.ettp.name"));
    }

2、使用org.springframework.core.io.support.PropertiesLoaderUtils;

    @Test
    public void testReadProperties() throws IOException {
        Properties properties = PropertiesLoaderUtils.loadAllProperties("resource.properties");
        String name = properties.getProperty("com.tsinkai.ettp.name");
        System.out.println(name);
    }

3、使用java.util.ResourceBundle;

    @Test
    public void testReadProperties2() throws IOException {
        ResourceBundle resourceBundle = ResourceBundle.getBundle("resource");
        String name = resourceBundle.getString("com.tsinkai.ettp.name");
        System.out.println(name);
    }

4、使用spring注解创建资源类

资源类：

package com.imooc.pojo;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;

@Configuration
@ConfigurationProperties(prefix="com.imooc.opensource")//属性前缀
@PropertySource(value="classpath:resource.properties")//文件路径
public class Resource {
    private String name;
    private String website;
    private String language;

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getWebsite() {
        return website;
    }
    public void setWebsite(String website) {
        this.website = website;
    }
    public String getLanguage() {
        return language;
    }
    public void setLanguage(String language) {
        this.language = language;
    }
}

调用：

package com.tsinkai.ettp;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import com.tsinkai.ettp.common.Resource;

@RunWith(SpringRunner.class)
@SpringBootTest
public class EttpCustomApplicationTests {

    @Autowired
    Resource customResource;

    @Test
    public void readResource() {
        Resource bean = new Resource();
        BeanUtils.copyProperties(customResource, bean);
        System.out.println(bean.getName());
    }
}