您定义的n和count没有看懂，而且调用过程中产生角标越界异常，我使用的JDK是1.8。自己私下改了代码，加了注释，希望能给您的开源项目做贡献。

java/05_array/Array.java

@@ -7,53 +7,83 @@
  * Author: Zheng
  */
 public class Array {
-  private int data[];
-  private int n;
-  private int count;
-
-  public Array(int capacity) {
-    data = new int[capacity];
-    n = capacity;
-    count = 0;
-  }
-
-  public int find(int index) {
-    if (index < 0 || index >= count ) return -1;
-    return data[index];
-  }
-
-  public boolean delete(int index) {
-    if (index < 0  || index >= count) return false;
-    for(int i = index + 1; i < count; ++i) {
-      data[i-1] = data[i];
+    //定义整型数据data保存数据
+    public int data[];
+    //定义数组长度
+    private int n;
+    //定义中保存的数据个数
+    private int count;
+
+    //构造方法，定义数组大小
+    public Array(int capacity){
+        this.data = new int[]{0,1,2,3,4};
+        this.n = capacity;
+        this.count=capacity;
+    }
+
+    //根据索引，找到数据中的元素并返回
+    public int find(int index){
+        if (index<0 || index>=count) return -1;
+        return data[index];
+    }
+
+    //根据索引，删除数组中元素
+    public boolean delete(int index){
+        if (index<0 || index >=count) return false;
+        //从删除位置开始，将后面的元素向前移动一位
+        for (int i=index+1; i<count; ++i){
+            data[i-1] = data[i];
+        }
+        //删除数组末尾元素  这段代码不需要也可以
+        /*int[] arr = new int[count-1];
+        for (int i=0; i<count-1;i++){
+            arr[i] = data[i];
+        }
+        this.data = arr;*/
+
+
+        --count;
+        return true;
     }
-    --count;
-    return true;
-  }
 
-  public boolean insert(int index, int value) {
-    if (index < 0 || index >= count) return false;
-    if (count == n) return false;
+    //向数组中插入一个元素
+    public boolean insert(int index, int value){
+        if (index<0 || index>=count) return false;
+//        if (count == n) return false;不是太懂
+        //数组长度增加1
+        int[] arr = new int[count+1];
+        for (int i = 0; i < data.length; i++) {
+            arr[i] = data[i];
+        }
+        data=arr;
+
+        for (int i = count-1; i>=index; --i){
+            data[i+1] = data[i];
+        }
+        data[index] = value;
+        ++count;
+        return true;
+    }
 
-    for (int i = count - 1; i >= index; --i) {
-      data[i+1] = data[i];
+    public boolean insertToTail(int value) {
+//        if (count == n) return false;不是太懂
+        //数组长度增加1
+        int[] arr = new int[count+1];
+        for (int i = 0; i < data.length; i++) {
+            arr[i] = data[i];
+        }
+        data=arr;
+        data[count++] = value;
+        return true;
     }
-    data[index] = value;
-    ++count;
-    return true;
-  }
-
-  public boolean insertToTail(int value) {
-    if (count == n) return false;
-    data[count++] = value;
-    return true;
-  }
-
-  public void printAll() {
-    for (int i = 0; i < count; ++i) {
-      System.out.print(data[i] + " ");
+
+    public void printAll() {
+        for (int i = 0; i < count; ++i) {
+            System.out.print(data[i] + " ");
+        }
+        System.out.println();
     }
-    System.out.println();
-  }
+
+
 
 }