2.2)添加依赖

如果使用maven构建项目，可以直接添加如下坐标下载依赖jar。

maven pom.xml

    <!-- 补全依赖 -->
    <!-- 1：日志； java日志：slf4j，log4j，logback，common-logging
        slf4j接口/规范
        log4j,logback,common-logging，实现
        此处使用slf4j+logback -->
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>1.7.6</version>
    </dependency>

    <!-- 实现slf4j日志 -->
    <dependency>
        <groupId>ch.qos.logback</groupId>
        <artifactId>logback-classic</artifactId>
        <version>1.1.1</version>
    </dependency> 

    <!-- HttpClient -->
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.3.6</version>
    </dependency>
    <!-- http://mvnrepository.com/artifact/org.apache.httpcomponents/httpmime -->
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpmime</artifactId>
        <version>4.3.6</version>
    </dependency>

    <!-- JSON -->
    <dependency>
        <groupId>org.codehaus.jackson</groupId>
        <artifactId>jackson-mapper-asl</artifactId>
        <version>1.9.13</version>
    </dependency>
    <!-- XML -->
    <!-- http://mvnrepository.com/artifact/com.thoughtworks.xstream/xstream -->
    <dependency>
        <groupId>com.thoughtworks.xstream</groupId>
        <artifactId>xstream</artifactId>
        <version>1.4.7</version>
    </dependency>
    <!-- IO -->
    <!-- http://mvnrepository.com/artifact/commons-io/commons-io -->
    <dependency>
        <groupId>commons-io</groupId>
        <artifactId>commons-io</artifactId>
        <version>2.4</version>
    </dependency>

如果不是maven构建的项目，可以自行下载相应的jar包，放在WEB-INF/lib文件夹下。

如果与项目中的jar包冲突或重复，只留一个就可以了~