diff --git a/problems/0042.接雨水.md b/problems/0042.接雨水.md
index 235776a0..b3ee84fd 100644
--- a/problems/0042.接雨水.md
+++ b/problems/0042.接雨水.md
@@ -365,7 +365,31 @@ public:
 ## 其他语言版本 
 
 Java: 
+双指针法
+```java
+class Solution {
+    public int trap(int[] height) {
+        int sum = 0;
+        for (int i = 0; i < height.length; i++) {
+            // 第一个柱子和最后一个柱子不接雨水
+            if (i==0 || i== height.length - 1) continue;
+            
+            int rHeight = height[i]; // 记录右边柱子的最高高度
+            int lHeight = height[i]; // 记录左边柱子的最高高度
+            for (int r = i+1; r < height.length; r++) {
+                if (height[r] > rHeight) rHeight = height[r];
+            }
+            for (int l = i-1; l >= 0; l--) {
+                if(height[l] > lHeight) lHeight = height[l];
+            }
+            int h = Math.min(lHeight, rHeight) - height[i];
+            if (h > 0) sum += h;
+        }
+        return sum;
 
+    }
+}
+```
 Python:
 
 双指针法