Table of Contents

Java Convert String to Boolean

對包含 boolean 的字串進行運算時，通常會使用轉換成 boolean ，從文本字段或文本區域讀取資料時，輸入的資料都會作為字串接收，將字串轉換為 boolean ，可以使用 parseBoolean 、 valueOf 、 getBoolean 等方法進行操作， Java String Boolean 任務是將該字串轉換為布林，本篇增加了範例，並透過單元測試來驗證產出結果。

檔案目錄

./
   +- src
       +- test
       |   +- org
       |       +- ruoxue
       |           +- java_147
       |               +- conversion
       |                   +- string
       |                       +- StringToBooleanTest.java

單元測試

Java String to Boolean 提供字串轉換成布林等操作。

parseBoolean

Java String to Boolean 使用 Boolean.parseBoolean 轉換成布林。

	@Test
	public void parseBoolean() {
		String value = "true";
		boolean result = Boolean.parseBoolean(value);
		System.out.println(result);
		assertEquals(true, result);

		value = "True";
		result = Boolean.parseBoolean(value);
		System.out.println(result);
		assertEquals(true, result);

		value = "TRUE";
		result = Boolean.parseBoolean(value);
		System.out.println(result);
		assertEquals(true, result);

		value = "ok";
		result = Boolean.parseBoolean(value);
		System.out.println(result);
		assertEquals(false, result);
	}

true
true
true
false

valueOf

Java String to Boolean 使用 Boolean.valueOf 轉換成布林。

	@Test
	public void valueOf() {
		String value = "true";
		Boolean result = Boolean.valueOf(value);
		System.out.println(result);
		assertEquals(true, result.booleanValue());

		value = "True";
		result = Boolean.valueOf(value);
		System.out.println(result);
		assertEquals(true, result.booleanValue());

		value = "TRUE";
		result = Boolean.valueOf(value);
		System.out.println(result);
		assertEquals(true, result.booleanValue());

		value = "ok";
		result = Boolean.valueOf(value);
		System.out.println(result);
		assertEquals(false, result.booleanValue());
	}

true
true
true
false

getBoolean

Java String to Boolean 使用 Boolean.getBoolean 從 System Property 讀取設定，轉換成布林。

	@Test
	public void getBoolean() {
		String value = "TEST_MODE";
		boolean result = Boolean.getBoolean(value);
		System.out.println(result);
		assertEquals(false, result);

		System.setProperty("TEST_MODE", "true");
		result = Boolean.getBoolean(value);
		System.out.println(result);
		assertEquals(true, result);

		System.setProperty("TEST_MODE", "True");
		result = Boolean.getBoolean(value);
		System.out.println(result);
		assertEquals(true, result);

		System.setProperty("TEST_MODE", "TRUE");
		result = Boolean.getBoolean(value);
		System.out.println(result);
		assertEquals(true, result);

		System.setProperty("TEST_MODE", "ok");
		result = Boolean.getBoolean(value);
		System.out.println(result);
		assertEquals(false, result);
	}

false
true
true
true
false

StringToBooleanTest.java

Convert String to Boolean in Java 新增單元測試，驗證是否符合預期。

package org.ruoxue.java_147.conversion.string;

import static org.junit.Assert.*;

import org.junit.Test;

public class StringToBooleanTest {

	@Test
	public void parseBoolean() {
		String value = "true";
		boolean result = Boolean.parseBoolean(value);
		System.out.println(result);
		assertEquals(true, result);

		value = "True";
		result = Boolean.parseBoolean(value);
		System.out.println(result);
		assertEquals(true, result);

		value = "TRUE";
		result = Boolean.parseBoolean(value);
		System.out.println(result);
		assertEquals(true, result);

		value = "ok";
		result = Boolean.parseBoolean(value);
		System.out.println(result);
		assertEquals(false, result);
	}

	@Test
	public void valueOf() {
		String value = "true";
		Boolean result = Boolean.valueOf(value);
		System.out.println(result);
		assertEquals(true, result.booleanValue());

		value = "True";
		result = Boolean.valueOf(value);
		System.out.println(result);
		assertEquals(true, result.booleanValue());

		value = "TRUE";
		result = Boolean.valueOf(value);
		System.out.println(result);
		assertEquals(true, result.booleanValue());

		value = "ok";
		result = Boolean.valueOf(value);
		System.out.println(result);
		assertEquals(false, result.booleanValue());
	}

	@Test
	public void getBoolean() {
		String value = "TEST_MODE";
		boolean result = Boolean.getBoolean(value);
		System.out.println(result);
		assertEquals(false, result);

		System.setProperty("TEST_MODE", "true");
		result = Boolean.getBoolean(value);
		System.out.println(result);
		assertEquals(true, result);

		System.setProperty("TEST_MODE", "True");
		result = Boolean.getBoolean(value);
		System.out.println(result);
		assertEquals(true, result);

		System.setProperty("TEST_MODE", "TRUE");
		result = Boolean.getBoolean(value);
		System.out.println(result);
		assertEquals(true, result);

		System.setProperty("TEST_MODE", "ok");
		result = Boolean.getBoolean(value);
		System.out.println(result);
		assertEquals(false, result);
	}
}

心得分享

String to Boolean in Java 使用 Boolean.parseBoolean 方法在將 String 轉換為 boolean 基本型別，要將 String 轉換為 Boolean 物件，則可以使用傳回 Boolean 實例的 Boolean.valueOf 方法，字串必須包含 true ，忽略大小寫， Convert String to Boolean in Java 提供將 String 實例轉換為 boolean 或 Boolean 實例的多種方法。