类型转换会遇到的坑

Author: enjoyCoding666

src/main/java/com/string/StringToIntegerDemo.java

@@ -0,0 +1,44 @@
+package com.string;
+
+import org.apache.commons.lang.ObjectUtils;
+import org.apache.commons.lang.StringUtils;
+import org.apache.commons.lang.math.NumberUtils;
+
+/**
+ * @Author: EnjoyCoding
+ * @Date: 2020\3\30 0030 23:58
+ * @Description:
+ */
+public class StringToIntegerDemo {
+
+
+	public static void main(String[] args) {
+//		objectToString();
+//		nullToEmpty();
+//		strToInteger();
+		integerValueOfDemo();
+	}
+
+	public static void nullToEmpty() {
+		Object object=null;
+		String str = ObjectUtils.toString(object);
+//		String str = ObjectUtils.toString(object,null);
+		System.out.println("值为："+str);
+	}
+
+	public static void strToInteger() {
+		String str="abc";
+		//str不为数字时，设置默认值为 0
+		int num = NumberUtils.toInt(str);
+		//str不为数字时，设置默认值为其他值
+		int defaultNum=NumberUtils.toInt(str,123);
+	}
+
+	public static void integerValueOfDemo() {
+		String str="123";
+//		String str="";
+		//str为非数字字符串时，报错： NumberFormatException:""
+		Integer value = Integer.valueOf(str);
+		System.out.println(value);
+	}
+}