处理MQTT消息

fys-modules/fys-app/src/main/java/com/fuyuanshen/app/domain/vo/Main.java

@@ -0,0 +1,52 @@
+package com.fuyuanshen.app.domain.vo;
+
+import java.io.*;
+import java.nio.charset.StandardCharsets;
+import java.util.TimeZone;
+
+public class Main {
+    public static void main(String[] args) throws IOException {
+
+        String[] availableIDs = TimeZone.getAvailableIDs();
+        for (String id : availableIDs) {
+            System.out.println(id);
+        }
+
+        byte[] data = "hello, world!".getBytes(StandardCharsets.UTF_8);
+        try (CountInputStream input = new CountInputStream(new ByteArrayInputStream(data))) {
+            int n;
+            while ((n = input.read()) != -1) {
+                System.out.println((char)n);
+            }
+            System.out.println("Total read " + input.getBytesRead() + " bytes");
+        }
+    }
+}
+
+class CountInputStream extends FilterInputStream {
+    private int count = 0;
+
+    CountInputStream(InputStream in) {
+        super(in);
+    }
+
+    public int getBytesRead() {
+        return this.count;
+    }
+
+    public int read() throws IOException {
+        int n = in.read();
+        if (n != -1) {
+            this.count ++;
+        }
+        return n;
+    }
+
+    public int read(byte[] b, int off, int len) throws IOException {
+        int n = in.read(b, off, len);
+        if (n != -1) {
+            this.count += n;
+        }
+        return n;
+    }
+}