一些javaweb开发常用工具类

1.StringUtils工具类：（判断string是否为空和空字符串）

<dependency>      <groupId>org.apache.commons</groupId>      <artifactId>commons-lang3</artifactId>      <version>3.5</version>    </dependency>

StringUtils.isNotBlank(a);

StringUtils.isBlank(a);

StringUtils.isEmpty(a);

StringUtils.isNotBlank(a);

2.CollectionUtils工具类：（判断集合是否为空）

<dependency>      <groupId>commons-collections</groupId>      <artifactId>commons-collections</artifactId>      <version>3.2.1</version>    </dependency>

CollectionUtils.isNotEmpty(cartList);

CollectionUtils.isEmpty(cartList);

3.guava的应用

<dependency>      <groupId>com.google.guava</groupId>      <artifactId>guava</artifactId>      <version>20.0</version>    </dependency>

List<CartProductVo> cartProductVoList = Lists.newArrayList();

Set<String> PRICE_ASC_DESC = Sets.newHashSet("price_desc","price_asc");

//gavan中的方法将字符串用逗号分割转换成list集合里去

List<String> productList = Splitter.on(",").splitToList(productIds);