diff --git a/parser/util.go b/parser/util.go
index 3abdd32..33de155 100644
--- a/parser/util.go
+++ b/parser/util.go
@@ -17,7 +17,7 @@ func getStrValueFromExpression(expr *Expression) []string {
 			return results
 		}
 		results = values
-		if expr.Symbol == PLUS {
+		if expr.Symbol == PLUS && expr.Next != nil {
 			var tmpSlice []string
 			nextStrs := getStrValueFromExpression(expr.Next)
 			for _, str := range nextStrs {
@@ -35,7 +35,7 @@ func getStrValueFromExpression(expr *Expression) []string {
 			return results
 		}
 
-		if expr.Symbol == PLUS {
+		if expr.Symbol == PLUS && expr.Next != nil {
 			nextStrs := getStrValueFromExpression(expr.Next)
 			if len(nextStrs) == 0 {
 				return []string{result}
@@ -80,7 +80,7 @@ func (f *FuncBlock) getValueFromCallExpr(argumentIndex int) []string {
 				}
 			} else if arg.RuleIndex == javaAntlr.JavaParserRULE_literal {
 				values = append(values, strings.Trim(arg.Content, "\""))
-				if arg.Symbol == PLUS {
+				if arg.Symbol == PLUS && arg.Next != nil {
 					var tmpSlice []string
 					nextStrs := getStrValueFromExpression(arg.Next)
 					for _, str := range nextStrs {
@@ -148,7 +148,7 @@ func GetSqlsFromVisitor(ctx *JavaVisitor) []string {
 		// 参数为变量
 		if arg.RuleIndex == javaAntlr.JavaParserRULE_identifier {
 			sqls = append(sqls, getVariableValueFromTree(arg.Content, expression.Node)...)
-			if arg.Symbol == PLUS {
+			if arg.Symbol == PLUS && arg.Next != nil {
 				tmpSlice := []string{}
 				nextSqls := getVariableValueFromTree(arg.Next.Content, expression.Node)
 				for _, str := range nextSqls {
@@ -168,7 +168,7 @@ func GetSqlsFromVisitor(ctx *JavaVisitor) []string {
 				continue
 			}
 			sqls = append(sqls, sql)
-			if arg.Symbol == PLUS {
+			if arg.Symbol == PLUS && arg.Next != nil {
 				tmpSlice := []string{}
 				nextSqls := getVariableValueFromTree(arg.Next.Content, expression.Node)
 				for _, str := range nextSqls {
diff --git a/parser/util_test.go b/parser/util_test.go
new file mode 100644
index 0000000..8150ad3
--- /dev/null
+++ b/parser/util_test.go
@@ -0,0 +1,178 @@
+package parser
+
+import (
+	"os"
+	"testing"
+)
+
+// TestSimplePanicFix 简单测试修复是否有效
+func TestSimplePanicFix(t *testing.T) {
+	// 创建一个会导致panic的Expression
+	expr := &Expression{
+		Content:   "\"SELECT * FROM users\"",
+		RuleIndex: 52, // JavaParserRULE_literal
+		Symbol:    "+",
+		Next:      nil, // 这里是nil，修复前会导致panic
+	}
+
+	// 测试修复后的函数不会panic
+	defer func() {
+		if r := recover(); r != nil {
+			t.Errorf("函数仍然panic: %v", r)
+		}
+	}()
+
+	// 调用修复后的函数
+	result := getStrValueFromExpression(expr)
+
+	// 验证函数正常返回（不panic）
+	if result == nil {
+		t.Error("结果不应该为nil")
+	}
+
+	// 验证返回了正确的字符串（因为Next为nil，应该返回原始字符串）
+	if len(result) == 1 && result[0] != "SELECT * FROM users" {
+		t.Errorf("期望: SELECT * FROM users, 实际: %s", result[0])
+	}
+}
+
+// TestGetSqlFromJavaFile 测试GetSqlFromJavaFile方法的各种场景
+func TestGetSqlFromJavaFile(t *testing.T) {
+	testCases := []struct {
+		name        string
+		javaCode    string
+		shouldPanic bool
+	}{
+		{
+			name: "包含null拼接的表达式",
+			javaCode: `
+public class TestClass {
+    public void testMethod() {
+        String sql = "SELECT * FROM users" + null;
+        executeQuery(sql);
+    }
+    
+    private void executeQuery(String sql) {
+        // JDBC调用
+    }
+}`,
+			shouldPanic: false,
+		},
+		{
+			name: "不完整的表达式_加号后换行",
+			javaCode: `
+public class TestClass {
+    public void testMethod() {
+        String sql = "SELECT * FROM users" + 
+        executeQuery(sql);
+    }
+    
+    private void executeQuery(String sql) {
+        // JDBC调用
+    }
+}`,
+			shouldPanic: false, // 修复后不应该panic
+		},
+		{
+			name: "正常的多行表达式",
+			javaCode: `
+public class TestClass {
+    public void testMethod() {
+        String sql = "SELECT * FROM users" + 
+                     " WHERE id = 1";
+        executeQuery(sql);
+    }
+    
+    private void executeQuery(String sql) {
+        // JDBC调用
+    }
+}`,
+			shouldPanic: false,
+		},
+		{
+			name: "复杂的多行拼接",
+			javaCode: `
+public class TestClass {
+    public void testMethod() {
+        String sql = "SELECT " + 
+                     "id, name, email " +
+                     "FROM users " +
+                     "WHERE status = 'active'";
+        executeQuery(sql);
+    }
+    
+    private void executeQuery(String sql) {
+        // JDBC调用
+    }
+}`,
+			shouldPanic: false,
+		},
+		{
+			name: "语法错误的表达式",
+			javaCode: `
+public class TestClass {
+    public void testMethod() {
+        String sql = "SELECT * FROM users" + ; // 语法错误
+        executeQuery(sql);
+    }
+    
+    private void executeQuery(String sql) {
+        // JDBC调用
+    }
+}`,
+			shouldPanic: false, // 修复后不应该panic，即使语法错误
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// 创建临时文件
+			tmpFile, err := os.CreateTemp("", "test_*.java")
+			if err != nil {
+				t.Fatalf("创建临时文件失败: %v", err)
+			}
+			defer os.Remove(tmpFile.Name())
+
+			// 写入Java代码
+			if _, err := tmpFile.WriteString(tc.javaCode); err != nil {
+				t.Fatalf("写入Java代码失败: %v", err)
+			}
+			tmpFile.Close()
+
+			// 测试GetSqlFromJavaFile函数不会panic
+			defer func() {
+				if r := recover(); r != nil {
+					if !tc.shouldPanic {
+						t.Errorf("测试用例 %s 意外panic: %v", tc.name, r)
+					}
+				}
+			}()
+
+			// 调用函数
+			sqls, err := GetSqlFromJavaFile(tmpFile.Name())
+			if err != nil {
+				t.Logf("解析错误（可能正常）: %v", err)
+			}
+
+			// 验证函数正常返回（不panic）
+			if sqls == nil {
+				t.Error("结果不应该为nil")
+			}
+		})
+	}
+}
+
+// BenchmarkPanicFix 性能测试确保修复不影响性能
+func BenchmarkPanicFix(b *testing.B) {
+	expr := &Expression{
+		Content:   "\"SELECT * FROM users\"",
+		RuleIndex: 52,
+		Symbol:    "+",
+		Next:      nil,
+	}
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		getStrValueFromExpression(expr)
+	}
+}