File类 是专门通过对象操作本地文件
能够关联本地文件进行 文件信息的处理

构造方法:

  1. 1.public File(String pathname)<br /> 参数传入一个路径 构造一个File对象![image.png](https://cdn.nlark.com/yuque/0/2022/png/28889470/1655054243003-c58a10ed-aeb7-4ba5-ae98-07037370c1fd.png#clientId=u1e1b4ce5-0ddf-4&crop=0&crop=0&crop=1&crop=1&from=paste&height=185&id=u102f68df&margin=%5Bobject%20Object%5D&name=image.png&originHeight=231&originWidth=501&originalType=binary&ratio=1&rotation=0&showTitle=false&size=20440&status=done&style=none&taskId=ua4d3b6c0-81d7-41e3-9a1c-d37c537f7c7&title=&width=400.8)![image.png](https://cdn.nlark.com/yuque/0/2022/png/28889470/1655054412596-f485e6ff-96cc-45d6-9e11-1ce6d0f327a0.png#clientId=u1e1b4ce5-0ddf-4&crop=0&crop=0&crop=1&crop=1&from=paste&height=123&id=u33805714&margin=%5Bobject%20Object%5D&name=image.png&originHeight=256&originWidth=906&originalType=binary&ratio=1&rotation=0&showTitle=false&size=33214&status=done&style=none&taskId=u50087aad-57f9-4817-99bc-c1c53655118&title=&width=436)<br /> 2.public File(String parent,String child)<br /> 父路径和子路径分开写:<br /> 子路径就有可能变量 父路径可以通过传参来写<br /> 传入父路径 和子路径的 字符串 构造一个File对象<br />![image.png](https://cdn.nlark.com/yuque/0/2022/png/28889470/1655134275829-05829692-1555-47b6-9d14-0b5e67fed30a.png#clientId=ue8420ab4-17a1-4&crop=0&crop=0&crop=1&crop=1&from=paste&height=146&id=u8f1a4fce&margin=%5Bobject%20Object%5D&name=image.png&originHeight=183&originWidth=560&originalType=binary&ratio=1&rotation=0&showTitle=false&size=19709&status=done&style=none&taskId=u2d7d278e-8e57-453f-8b2d-a4594d41034&title=&width=448)<br /> 3.public File(File parent,String child)<br /> 传入父路径的File对象 传入子路径字符串![image.png](https://cdn.nlark.com/yuque/0/2022/png/28889470/1655134216016-7ab10ccd-87d1-494f-a432-eed58d736664.png#clientId=ue8420ab4-17a1-4&crop=0&crop=0&crop=1&crop=1&from=paste&height=179&id=u89617e91&margin=%5Bobject%20Object%5D&name=image.png&originHeight=224&originWidth=616&originalType=binary&ratio=1&rotation=0&showTitle=false&size=25332&status=done&style=none&taskId=u839800dc-5f9f-447f-95b4-15166aabd7f&title=&width=492.8)

File类的一些成员方法:

创建方法(3种):

1.public boolean createNewFile()

创建一个新文件 返回布尔值表示是否创建成功
如果路径中没有创建的文件 创建成功返回true
如果路径中已存在同名文件 文件已存在返回false
如果路径不存在则 直接报错
没有该文件时 创建成功返回true:image.png
已有同名文件再创建则返回false:image.png
路径不存在 则报错:image.png

2. public boolean mkdir() 创建一个新目录(文件夹)

        只能创建一层目录 否则返回false![image.png](https://cdn.nlark.com/yuque/0/2022/png/28889470/1655135461905-6adf2245-b140-4d42-8fb7-5bc9a8b25586.png#clientId=ue8420ab4-17a1-4&crop=0&crop=0&crop=1&crop=1&from=paste&height=206&id=u52a57eb0&margin=%5Bobject%20Object%5D&name=image.png&originHeight=257&originWidth=553&originalType=binary&ratio=1&rotation=0&showTitle=false&size=24822&status=done&style=none&taskId=ua9b0df7b-e732-4c86-98c9-80cfcd9d0c9&title=&width=442.4)<br />创建多层就不可以 返回false:![image.png](https://cdn.nlark.com/yuque/0/2022/png/28889470/1655135562648-3dd43b10-011c-4cbe-b0ea-c2545d30117e.png#clientId=ue8420ab4-17a1-4&crop=0&crop=0&crop=1&crop=1&from=paste&height=138&id=u04567e34&margin=%5Bobject%20Object%5D&name=image.png&originHeight=172&originWidth=555&originalType=binary&ratio=1&rotation=0&showTitle=false&size=15485&status=done&style=none&taskId=u5d0a6295-c8bb-4f04-9774-59938acb88c&title=&width=444)

3. public boolean mkdirs() 可以创建多层目录image.png

删除方法:

public boolean delete()<br />         如果file对象关联的是目录 则**目录必须为空才能删除**<br />      **   如果关联的是文件 则直接删除**<br /> 删除不走回收站 默认永久删除!!!!!!!!!!!!!!!!!<br />当前目录没有清空 则返回false![image.png](https://cdn.nlark.com/yuque/0/2022/png/28889470/1655135991283-5b9f4c6b-d2d4-4f23-8a40-418a2949f1d6.png#clientId=ue8420ab4-17a1-4&crop=0&crop=0&crop=1&crop=1&from=paste&height=206&id=uf7951be7&margin=%5Bobject%20Object%5D&name=image.png&originHeight=258&originWidth=573&originalType=binary&ratio=1&rotation=0&showTitle=false&size=23572&status=done&style=none&taskId=uee72fa6d-1ff3-45f2-943b-e00ef5e0551&title=&width=458.4)<br />目录清空则直接删除:![image.png](https://cdn.nlark.com/yuque/0/2022/png/28889470/1655136102467-a117cf71-57d0-4722-9365-acb890ca4d8b.png#clientId=ue8420ab4-17a1-4&crop=0&crop=0&crop=1&crop=1&from=paste&height=126&id=u8e0ccf9c&margin=%5Bobject%20Object%5D&name=image.png&originHeight=157&originWidth=575&originalType=binary&ratio=1&rotation=0&showTitle=false&size=14613&status=done&style=none&taskId=uf5532b7a-501f-4845-83ea-785d87e9224&title=&width=460)

重命名功能:

    public boolean renameTo(File dest)<br />        如果原目录跟目标目录一致  则直接重命名<br />        如果不一致就是剪切并且重命名<br />![image.png](https://cdn.nlark.com/yuque/0/2022/png/28889470/1655136323202-a570d43a-48f3-4b50-aa2a-db2a19046386.png#clientId=ue8420ab4-17a1-4&crop=0&crop=0&crop=1&crop=1&from=paste&height=225&id=u38a17290&margin=%5Bobject%20Object%5D&name=image.png&originHeight=281&originWidth=570&originalType=binary&ratio=1&rotation=0&showTitle=false&size=32445&status=done&style=none&taskId=u1d2cea6e-7390-4c75-bca2-62a2fb427ca&title=&width=456)