refactor

src/main/java/com/alibaba/druid/util/IOUtils.java

@@ -0,0 +1,76 @@
+package com.alibaba.druid.util;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.Reader;
+import java.io.StringWriter;
+import java.text.SimpleDateFormat;
+
+public class IOUtils {
+
+    public final static int DEFAULT_BUFFER_SIZE = 1024 * 4;
+
+    public static String read(Reader reader) {
+        try {
+
+            StringWriter writer = new StringWriter();
+
+            char[] buffer = new char[DEFAULT_BUFFER_SIZE];
+            int n = 0;
+            while (-1 != (n = reader.read(buffer))) {
+                writer.write(buffer, 0, n);
+            }
+
+            return writer.toString();
+        } catch (IOException ex) {
+            throw new IllegalStateException("read error", ex);
+        }
+    }
+
+    public static String read(Reader reader, int length) {
+        try {
+            char[] buffer = new char[length];
+
+            int offset = 0;
+            int rest = length;
+            int len;
+            while ((len = reader.read(buffer, offset, rest)) != -1) {
+                rest -= len;
+                offset += len;
+
+                if (rest == 0) {
+                    break;
+                }
+            }
+
+            return new String(buffer, 0, length - rest);
+        } catch (IOException ex) {
+            throw new IllegalStateException("read error", ex);
+        }
+    }
+
+    public static String toString(java.util.Date date) {
+        if (date == null) {
+            return null;
+        }
+        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
+        return format.format(date);
+    }
+
+    public static String getStackTrace(Throwable ex) {
+        StringWriter buf = new StringWriter();
+        ex.printStackTrace(new PrintWriter(buf));
+
+        return buf.toString();
+    }
+
+    public static String toString(StackTraceElement[] stackTrace) {
+        StringBuilder buf = new StringBuilder();
+        for (StackTraceElement item : stackTrace) {
+            buf.append(item.toString());
+            buf.append("\n");
+        }
+        return buf.toString();
+    }
+
+}