{"id":1309,"date":"2022-10-29T22:52:37","date_gmt":"2022-10-29T14:52:37","guid":{"rendered":"https:\/\/qaqaq.top\/?p=1309"},"modified":"2022-11-27T12:39:46","modified_gmt":"2022-11-27T04:39:46","slug":"io%e6%b5%81-io%e6%b5%81%e7%9a%84%e4%bd%93%e7%b3%bb%e7%bb%93%e6%9e%84%e3%80%81filereader%e8%af%bb%e5%85%a5%e6%95%b0%e6%8d%ae%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%93%8d%e4%bd%9c%e3%80%81filereader%e4%b8%ad","status":"publish","type":"post","link":"https:\/\/qaqaq.top\/?p=1309","title":{"rendered":"IO\u6d41-IO\u6d41\u7684\u4f53\u7cfb\u7ed3\u6784\u3001FileReader\u8bfb\u5165\u6570\u636e\u7684\u57fa\u672c\u64cd\u4f5c\u3001FileReader\u4e2d\u4f7f\u7528read(char[] cbuf)\u8bfb\u5165\u6570\u636e\u3001FileWriter\u5199\u51fa\u6570\u636e\u7684\u64cd\u4f5c\u3001\u4f7f\u7528FileReader\u548cFileWriter\u5b9e\u73b0\u6587\u672c\u6587\u4ef6\u7684\u590d\u5236\u3001\u5b57\u7b26\u6d41\u4e0d\u80fd\u5904\u7406\u56fe\u7247\u6587\u4ef6\u7684\u6d4b\u8bd5"},"content":{"rendered":"\n<pre class=\"wp-block-code\"><code>package top.qaqaq.java.P586;\r\n\r\nimport org.junit.jupiter.api.Test;\r\n\r\nimport java.io.*;\r\n\r\n\/**\r\n * \u4e00\u3001\u6d41\u7684\u5206\u7c7b\uff1a\r\n * 1. \u64cd\u4f5c\u6570\u636e\u5355\u4f4d\uff1a\u5b57\u8282\u6d41\u3001\u5b57\u7b26\u6d41\r\n * 2. \u6570\u636e\u7684\u6d41\u5411\uff1a\u8f93\u5165\u6d41\u3001\u8f93\u51fa\u6d41\r\n * 3. \u6d41\u7684\u89d2\u8272\uff1a\u8282\u70b9\u6d41\u3001\u5904\u7406\u6d41\r\n * &lt;p>\r\n * \u4e8c\u3001\u6d41\u7684\u4f53\u7cfb\u7ed3\u6784\r\n * \u62bd\u8c61\u57fa\u7c7b         \u8282\u70b9\u6d41\uff08\u6216\u6587\u4ef6\u6d41\uff09                               \u7f13\u51b2\u6d41\uff08\u5904\u7406\u6d41\u7684\u4e00\u79cd\uff09\r\n * InputStream      FileInputStream (read(char&#91;] buffer))           BufferedInputStream (read(char&#91;] buffer))\r\n * OutputStream     FileOutputStream (write(char&#91;] buffer,0,len))   BufferedOutputStream (write(char&#91;] buffer,0,len)) \/ flush()\r\n * Reader           FileReader (read(char&#91;] cbuf))                  BufferedReader (read(char&#91;] cbuf) \/ readLine())\r\n * Writer           FileWriter (write(char&#91;] cbuf,0,len))           BufferedWriter (write(char&#91;] cbuf,0,len)) \/ flush()\r\n *\r\n * @author RichieZhang\r\n * @create 2022-10-29 \u4e0b\u5348 7:55\r\n *\/\r\npublic class FileReaderWriterTest {\r\n\r\n    public static void main(String&#91;] args) {\r\n        File file = new File(\"hello.txt\");\/\/\u76f8\u8f83\u4e8e\u5f53\u524d\u5de5\u7a0b\r\n        System.out.println(file.getAbsolutePath());\r\n\r\n        File file1 = new File(\"Code\\\\hello.txt\");\r\n        System.out.println(file1.getAbsolutePath());\r\n    }\r\n\r\n    \/*\r\n    \u5c06Code\u4e0b\u7684hello.txt\u6587\u4ef6\u5185\u5bb9\u8bfb\u5165\u7a0b\u5e8f\u4e2d\uff0c\u5e76\u8f93\u51fa\u5230\u63a7\u5236\u53f0\r\n\r\n    \u8bf4\u660e\u70b9\uff1a\r\n    1. read()\u7684\u7406\u89e3\uff1a\u8fd4\u56de\u8bfb\u5165\u7684\u4e00\u4e2a\u5b57\u7b26\u3002\u5982\u679c\u8fbe\u5230\u6587\u4ef6\u672b\u5c3e\uff0c\u8fd4\u56de-1\r\n    2. \u5f02\u5e38\u7684\u5904\u7406\uff1a\u4e3a\u4e86\u4fdd\u8bc1\u6d41\u8d44\u6e90\u4e00\u5b9a\u53ef\u4ee5\u6267\u884c\u5173\u95ed\u64cd\u4f5c\u3002\u9700\u8981\u4f7f\u7528try-catch-finally\u5904\u7406\r\n    3. \u8bfb\u5165\u7684\u6587\u4ef6\u4e00\u5b9a\u8981\u5b58\u5728\uff0c\u5426\u5219\u5c31\u4f1a\u62a5FileNotFoundException\u3002\r\n\r\n     *\/\r\n    @Test\r\n    public void testFileReader() {\r\n        FileReader fr = null;\r\n        try {\r\n            \/\/1. \u5b9e\u4f8b\u5316File\u7c7b\u7684\u5bf9\u8c61\uff0c\u6307\u660e\u8981\u64cd\u4f5c\u7684\u6587\u4ef6\r\n            File file = new File(\"hello.txt\");\/\/\u76f8\u8f83\u4e8e\u5f53\u524dModule\r\n            \/\/2. \u63d0\u4f9b\u5177\u4f53\u7684\u6d41\r\n            fr = new FileReader(file);\r\n\r\n            \/\/3. \u6570\u636e\u7684\u8bfb\u5165\r\n            \/\/read():\u8fd4\u56de\u8bfb\u5165\u7684\u4e00\u4e2a\u5b57\u7b26\u3002\u5982\u679c\u8fbe\u5230\u6587\u4ef6\u672b\u5c3e\uff0c\u8fd4\u56de-1\r\n            \/\/\u65b9\u5f0f\u4e00\uff1a\r\n\/\/        int data = fr.read();\r\n\/\/        while (data != -1){\r\n\/\/            System.out.print((char) data);\r\n\/\/            data = fr.read();\r\n\/\/        }\r\n\r\n            \/\/\u65b9\u5f0f\u4e8c\uff1a\r\n            int data;\r\n            while ((data = fr.read()) != -1) {\r\n                System.out.print((char) data);\r\n            }\r\n        } catch (IOException e) {\r\n            e.printStackTrace();\r\n        } finally {\r\n            \/\/4. \u6d41\u7684\u5173\u95ed\u64cd\u4f5c\r\n\/\/            try {\r\n\/\/                if (fr != null)\r\n\/\/                    fr.close();\r\n\/\/            } catch (IOException e) {\r\n\/\/                e.printStackTrace();\r\n\/\/            }\r\n            \/\/\u6216\r\n            if (fr != null) {\r\n                try {\r\n                    fr.close();\r\n                } catch (IOException e) {\r\n                    e.printStackTrace();\r\n                }\r\n            }\r\n        }\r\n    }\r\n\r\n    \/\/\u5bf9read()\u64cd\u4f5c\u5347\u7ea7\uff1a\u4f7f\u7528read\u7684\u91cd\u8f7d\u65b9\u6cd5\r\n    @Test\r\n    public void testFileReader1() {\r\n        FileReader fr = null;\r\n        try {\r\n            \/\/1. File\u7c7b\u7684\u5b9e\u4f8b\u5316\r\n            File file = new File(\"hello.txt\");\r\n            \/\/2. FileReader \u6d41\u7684\u5b9e\u4f8b\u5316\r\n            fr = new FileReader(file);\r\n            \/\/3. \u8bfb\u5165\u7684\u64cd\u4f5c\r\n            \/\/read(char&#91;] cbuf):\u8fd4\u56de\u6bcf\u6b21\u8bfb\u5165cbuf\u6570\u7ec4\u4e2d\u7684\u5b57\u7b26\u7684\u4e2a\u6570\u3002\u5982\u679c\u8fbe\u5230\u6587\u4ef6\u672b\u5c3e\uff0c\u8fd4\u56de-1\r\n            char&#91;] cbuf = new char&#91;5];\r\n            int len;\r\n            while ((len = fr.read(cbuf)) != -1) {\r\n                \/\/\u65b9\u5f0f\u4e00\uff1a\r\n                \/\/\u9519\u8bef\u7684\u5199\u6cd5\r\n\/\/                for (int i = 0; i &lt; cbuf.length; i++){\r\n\/\/                    System.out.print(cbuf&#91;i]);\r\n\/\/                }\r\n                \/\/\u6b63\u786e\u7684\u5199\u6cd5\r\n\/\/                for (int i = 0; i &lt; len; i++){\r\n\/\/                    System.out.print(cbuf&#91;i]);\r\n\/\/                }\r\n\r\n                \/\/\u65b9\u5f0f\u4e8c\uff1a\r\n                \/\/\u9519\u8bef\u7684\u5199\u6cd5\uff0c\u5bf9\u5e94\u7740\u65b9\u5f0f\u4e00\u7684\u9519\u8bef\u7684\u5199\u6cd5\r\n\/\/                String str = new String(cbuf);\r\n\/\/                System.out.print(str);\r\n                \/\/\u6b63\u786e\u7684\u5199\u6cd5\r\n                String str = new String(cbuf, 0, len);\r\n                System.out.print(str);\r\n            }\r\n        } catch (IOException e) {\r\n            e.printStackTrace();\r\n        } finally {\r\n            if (fr != null) {\r\n                \/\/4. \u8d44\u6e90\u7684\u5173\u95ed\r\n                try {\r\n                    fr.close();\r\n                } catch (IOException e) {\r\n                    e.printStackTrace();\r\n                }\r\n\r\n            }\r\n        }\r\n    }\r\n\r\n    \/*\r\n    \u4ece\u5185\u5b58\u4e2d\u5199\u51fa\u6570\u636e\u5230\u786c\u76d8\u7684\u6587\u4ef6\u91cc\u3002\r\n\r\n    \u8bf4\u660e\uff1a\r\n    1. \u8f93\u51fa\u64cd\u4f5c\uff0c\u5bf9\u5e94\u7684File\u53ef\u4ee5\u4e0d\u5b58\u5728\u7684\u3002\u5e76\u4e0d\u4f1a\u62a5\u5f02\u5e38\r\n        File\u5bf9\u5e94\u7684\u786c\u76d8\u4e2d\u7684\u6587\u4ef6\u5982\u679c\u4e0d\u5b58\u5728\uff0c\u5728\u8f93\u51fa\u7684\u8fc7\u7a0b\u4e2d\uff0c\u4f1a\u81ea\u52a8\u521b\u5efa\u6b64\u6587\u4ef6\u3002\r\n        File\u5bf9\u5e94\u7684\u786c\u76d8\u4e2d\u7684\u6587\u4ef6\u5982\u679c\u5b58\u5728\uff1a\r\n                \u5982\u679c\u6d41\u4f7f\u7528\u7684\u6784\u9020\u5668\u662f\uff1aFileWriter(file,false) \/ FileWriter(file):\u5bf9\u539f\u6709\u6587\u4ef6\u7684\u8986\u76d6\r\n                \u5982\u679c\u6d41\u4f7f\u7528\u7684\u6784\u9020\u5668\u662f\uff1aFileWriter(file,true):\u4e0d\u4f1a\u5bf9\u539f\u6709\u6587\u4ef6\u8986\u76d6\uff0c\u800c\u662f\u5728\u539f\u6709\u6587\u4ef6\u57fa\u7840\u4e0a\u8ffd\u52a0\u5185\u5bb9\r\n     *\/\r\n    @Test\r\n    public void testFileWriter() {\r\n        FileWriter fw = null;\r\n        try {\r\n            \/\/1. \u63d0\u4f9bFile\u7c7b\u7684\u5bf9\u8c61\uff0c\u6307\u660e\u5199\u51fa\u5230\u7684\u6587\u4ef6\r\n            File file = new File(\"hello1.txt\");\r\n\r\n            \/\/2. \u63d0\u4f9bFileWriter\u7684\u5bf9\u8c61\uff0c\u7528\u4e8e\u6570\u636e\u7684\u5199\u51fa\r\n            fw = new FileWriter(file, false);\r\n\r\n            \/\/3. \u5199\u51fa\u7684\u64cd\u4f5c\r\n            fw.write(\"I have a dream!\\n\");\r\n            fw.write(\"you need to have a dream!\");\r\n        } catch (IOException e) {\r\n            e.printStackTrace();\r\n        } finally {\r\n            \/\/4. \u6d41\u8d44\u6e90\u7684\u5173\u95ed\r\n            if (fw != null) {\r\n\r\n                try {\r\n                    fw.close();\r\n                } catch (IOException e) {\r\n                    e.printStackTrace();\r\n                }\r\n            }\r\n        }\r\n    }\r\n\r\n    @Test\r\n    public void testFileReaderFileWriter() {\r\n        FileReader fr = null;\r\n        FileWriter fw = null;\r\n        try {\r\n            \/\/1. \u521b\u5efaFile\u7c7b\u7684\u5bf9\u8c61\uff0c\u6307\u660e\u8bfb\u5165\u548c\u5199\u51fa\u7684\u6587\u4ef6\r\n            File srcFile = new File(\"hello.txt\");\r\n            File destFile = new File(\"hello2.txt\");\r\n\r\n            \/\/\u4e0d\u80fd\u4f7f\u7528\u5b57\u7b26\u6d41\u6765\u5904\u7406\u56fe\u7247\u7b49\u5b57\u8282\u6570\u636e\r\n\/\/            File srcFile = new File(\"\u7231\u60c5\u4e0e\u53cb\u60c5.jpg\");\r\n\/\/            File destFile = new File(\"\u7231\u60c5\u4e0e\u53cb\u60c51.jpg\");\r\n\r\n            \/\/2. \u521b\u5efa\u8f93\u5165\u6d41\u548c\u8f93\u51fa\u6d41\u7684\u5bf9\u8c61\r\n            fr = new FileReader(srcFile);\r\n            fw = new FileWriter(destFile);\r\n\r\n            \/\/3. \u6570\u636e\u7684\u8bfb\u5165\u548c\u5199\u51fa\u64cd\u4f5c\r\n            char&#91;] cbuf = new char&#91;5];\r\n            int len;\/\/\u8bb0\u5f55\u6bcf\u6b21\u8bfb\u5165\u5230cbuf\u6570\u7ec4\u4e2d\u7684\u5b57\u7b26\u7684\u4e2a\u6570\r\n            while ((len = fr.read(cbuf)) != -1) {\r\n\r\n                \/\/\u6bcf\u6b21\u5199\u51faLen\u4e2a\u5b57\u7b26\r\n                fw.write(cbuf, 0, len);\r\n            }\r\n        } catch (IOException e) {\r\n            e.printStackTrace();\r\n        } finally {\r\n            \/\/4. \u5173\u95ed\u6d41\u8d44\u6e90\r\n            \/\/\u65b9\u5f0f\u4e00\uff1a\r\n\/\/            try {\r\n\/\/                if (fw != null)\r\n\/\/                    fw.close();\r\n\/\/            } catch (IOException e) {\r\n\/\/                e.printStackTrace();\r\n\/\/            } finally {\r\n\/\/                try {\r\n\/\/                    if (fr != null)\r\n\/\/                        fr.close();\r\n\/\/                } catch (IOException e) {\r\n\/\/                    e.printStackTrace();\r\n\/\/                }\r\n\/\/            }\r\n\r\n            \/\/\u65b9\u5f0f\u4e8c\uff1a\r\n            try {\r\n                if (fw != null)\r\n                    fw.close();\r\n            } catch (IOException e) {\r\n                e.printStackTrace();\r\n            }\r\n\r\n            try {\r\n                if (fr != null)\r\n                    fr.close();\r\n            } catch (IOException e) {\r\n                e.printStackTrace();\r\n            }\r\n        }\r\n\r\n    }\r\n}\r\n\r\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[46],"class_list":["post-1309","post","type-post","status-publish","format-standard","hentry","category-java-code","tag-java"],"_links":{"self":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1309"}],"collection":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1309"}],"version-history":[{"count":2,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1309\/revisions"}],"predecessor-version":[{"id":1314,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1309\/revisions\/1314"}],"wp:attachment":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1309"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1309"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1309"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}