【java_basic】:添加File

src/main/java/Lambada/BiFunctionTest.java

@@ -33,7 +33,7 @@ public int calculate(int num1, int num2, BiFunction<Integer, Integer, Integer> b
     @Test
     public void test1() {
         BiFunction<Integer, Integer, Integer> biFunction = (integer, integer2) -> addTwoSum(integer, integer2);
-        System.out.println(biFunction.apply(4,5));
+        System.out.println(biFunction.apply(4, 5));
     }
 
     @Test
@@ -51,4 +51,13 @@ public void test3() {
         Integer a = 534;
         System.out.println(534 == a);
     }
+
+    @Test
+
+    public void test4() {
+        int a = 10;
+        int b = 10;
+        System.out.println(++a + ", " + a);
+        System.out.println(b++ + ", " + b);
+    }
 }

src/main/java/java_basic/io/io2/file/FileList.java

@@ -0,0 +1,30 @@
+package java_basic.io.io2.file;
+
+import java.io.File;
+
+/**
+ * @author chenyuqun
+ * @date 2021/4/13 10:50 上午
+ */
+public class FileList {
+    public static void main(String[] args) {
+        File file = new File("./src/main/java/java_basic/io");
+        printFile(file);
+    }
+
+    public static void printFile(File file) {
+        if (file.isFile()) {
+            System.out.println("    " + file.getPath());
+            return;
+        }
+        if (!file.isDirectory()) {
+            throw new RuntimeException("文件既不是file,又不是directory: filePath: " + file.getPath());
+        }
+        System.out.println(file.getPath());
+        File[] files = file.listFiles();
+        assert files != null;
+        for (File fileInDirectory : files) {
+            printFile(fileInDirectory);
+        }
+    }
+}

src/main/java/java_basic/io/io2/file/FileMethod.java

@@ -0,0 +1,41 @@
+package java_basic.io.io2.file;
+
+import java.io.File;
+import java.io.IOException;
+
+/**
+ * @author chenyuqun
+ * @date 2021/4/13 10:08 上午
+ */
+public class FileMethod {
+
+    public static void main(String[] args) throws IOException {
+        checkMethod();
+        createMethod();
+    }
+
+    public static void checkMethod() {
+        File file = new File(".");
+        System.out.println(file.isDirectory());
+        System.out.println(file.isFile());
+        System.out.println(file.canRead());
+        System.out.println(file.canWrite());
+        System.out.println(file.canExecute());
+    }
+
+    public static void createMethod() throws IOException {
+        File file = new File("./src/main/java/java_basic/io/io2/createNewFile.txt");
+        if (file.createNewFile()) {
+            System.out.println("create file success");
+        }
+
+        if (file.delete()) {
+            System.out.println("delete file success");
+        }
+        System.out.println(file.getCanonicalPath());
+
+        File file2 = File.createTempFile("cyq-temp-", ".txt");
+        file2.deleteOnExit();
+        System.out.println(file2.getCanonicalPath());
+    }
+}

src/main/java/java_basic/io/io2/file/FilePath.java

@@ -0,0 +1,27 @@
+package java_basic.io.io2.file;
+
+import java.io.File;
+import java.io.IOException;
+
+/**
+ * @author chenyuqun
+ * @date 2021/4/13 9:29 上午
+ */
+public class FilePath {
+    public static void main(String[] args) throws IOException {
+        File file = new File("..");
+        // 构造方法传入的路径
+        System.out.println(file.getPath());
+        // 绝对路径
+        System.out.println(file.getAbsolutePath());
+        // 规范化路径
+        System.out.println(file.getCanonicalPath());
+        System.out.println();
+
+        File file2 = new File("../chenyuqun");
+        System.out.println(file2.getPath());
+        System.out.println(file2.getAbsolutePath());
+        System.out.println(file2.getCanonicalPath());
+
+    }
+}

src/main/java/java_basic/io/io2/file/FileSeparator.java

@@ -0,0 +1,16 @@
+package java_basic.io.io2.file;
+
+import java.io.File;
+
+/**
+ * @author chenyuqun
+ * @date 2021/4/13 9:33 上午
+ */
+public class FileSeparator {
+    public static void main(String[] args) {
+        // 多个路径的分隔符
+        System.out.println(File.pathSeparator);
+        // 路径中的分隔符
+        System.out.println(File.separator);
+    }
+}

src/main/java/java_basic/io/io2/file/PathTest.java

@@ -0,0 +1,27 @@
+package java_basic.io.io2.file;
+
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+/**
+ * @author chenyuqun
+ * @date 2021/4/13 11:27 上午
+ */
+public class PathTest {
+    public static void main(String[] args) {
+        Path path = Paths.get(".","src","main","java","java_basic","io");
+        System.out.println(path);
+        // 转换为绝对路径
+        System.out.println(path.toAbsolutePath());
+        // 转换为规范路径
+        System.out.println(path.normalize());
+        // 转换为File对象
+        System.out.println(path.toFile().getName());
+
+        // 直接遍历path
+        System.out.println("path: ");
+        for (Path path1 : Paths.get(".").toAbsolutePath()) {
+            System.out.println(path1);
+        }
+    }
+}

src/main/java/java_basic/io/io2/file/package-info.java

@@ -0,0 +1,13 @@
+package java_basic.io.io2.file;
+
+/**
+ * 参考：
+ * https://www.liaoxuefeng.com/wiki/1252599548343744/1298069154955297
+ * File对象：
+ * 1、文件三个的路径:传入的路径，绝对路径，规范化路径, {@link java_basic.io.io2.file.FilePath}
+ * 2、文件分隔符：pathSeparator, separator, {@link java_basic.io.io2.file.FileSeparator}
+ * 3、文件方法；is、can 方法, create方法, {@link java_basic.io.io2.file.FileMethod}
+ * 4、Path对象:创建、转换成别的路径、转换成File、直接遍历path, {@link java_basic.io.io2.file.PathTest}
+ * 5、小demo：列举出一个目录下的所有文件名 {@link java_basic.io.io2.file.FileList}
+ */
+

src/main/java/javabase/stringTest/StringTest.java

@@ -1,7 +1,7 @@
 package javabase.stringTest;
 
 import com.google.common.base.Strings;
-import com.sun.deploy.util.StringUtils;
+import com.sun.javafx.binding.StringFormatter;
 import org.junit.Test;
 
 import java.time.Instant;
@@ -64,4 +64,10 @@ public void testSplit() {
             System.out.println(i);
         }
     }
+
+    @Test
+    public void testFormat() {
+        String desc = "hello, {}";
+        StringFormatter.format(desc, "world");
+    }
 }