查看“正则表达式 Pattern 类”的源代码

https://www.bilibili.com/video/BV1Eq4y1E79W/?p=18

Pattern 对象是一个正则表达式对象。

Pattern 没有公共构造方法。

要创建一个 Pattern 对象，调用其公共静态方法，它返回一个 Pattern 对象。

该方法接受一个正则表达式作为它的第一个参数，比如：<syntaxhighlight lang="java">
Pattern pattern = Pattern.compile(regStr);
</syntaxhighlight>

=== 示例：演示 matches 方法进行整体匹配判断 ===

==== 示例1： ====
<syntaxhighlight lang="java">
import java.util.regex.Pattern;

public class PatternMethod {

    public static void main(String[] args) {

        String content = "hello abc hello，韩顺平教育";

        String regStr = "hello";

        boolean matches = Pattern.matches(regStr, content);

        System.out.println("整体匹配=" + matches);

    }

}
</syntaxhighlight><syntaxhighlight lang="console">
整体匹配=false
</syntaxhighlight>





==== 示例2： ====
<syntaxhighlight lang="java">
import java.util.regex.Pattern;

public class PatternMethod {

    public static void main(String[] args) {

        String content = "hello abc hello，韩顺平教育";

        String regStr = "hello.*";

        boolean matches = Pattern.matches(regStr, content);

        System.out.println("整体匹配=" + matches);

    }

}
</syntaxhighlight><syntaxhighlight lang="console">
整体匹配=true
</syntaxhighlight>





==== 示例3： ====
<syntaxhighlight lang="java">
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RegExp11 {

    public static void main(String[] args) {

        String content = "edu.3dsmax.tech/yg/bitibiti/my6652/pc/qg/05-51/index.html#201211-1?track_id=jMc0jn-hm-yHrNfVad37YdhOUh41XYmjlss9zocM26gspY5ArwWuxb4wYWpmh2Q7doU0wLkViEhUIO1qNtukyAgake2jG1bTd23IR57XzV83E9bAXWkStcAh4j9Dz7a87ThGIqgdCZ2zpQy33a0SVNMfmJLSNnDzJ71TU68Rc-3PKE7VA3kYzjk4RrKU";

        /**
         * 思路：
         * 1、先确定 url 的开始部分 https:// | http://  ((http|https)://)
         * 2、确定域名的部分 ([\w-]+\.)+[\w-]+
         * 3、匹配域名后面的路径和参数  (\\/[\\w-?=&/%.#]*)?
         */
        String regStr = "((http|https)://)?([\\w-]+\\.)+[\\w-]+(\\/[\\w-?=&/%.#]*)?"; //注意：[.]表示匹配就是 . 本身

        Pattern pattern = Pattern.compile(regStr);

        Matcher matcher = pattern.matcher(content);

        if (matcher.find()) {

            System.out.println("满足格式");

        } else {

            System.out.println("不满足格式");

        }

        System.out.println("是否整体匹配:" + Pattern.matches(regStr, content));

    }

}
</syntaxhighlight><syntaxhighlight lang="console">
满足格式
true
</syntaxhighlight>


==== 示例4： ====
<syntaxhighlight lang="java">
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RegExp11 {

    public static void main(String[] args) {

        String content = "edu.3dsmax.tech/yg/bitibiti/my6652/pc/qg/05-51/index.html#201211-1?track_id=jMc0jn-hm-yHrNfVad37YdhOUh41XYmjlss9zocM26gspY5ArwWuxb4wYWpmh2Q7doU0wLkViEhUIO1qNtukyAgake2jG1bTd23IR57XzV83E9bAXWkStcAh4j9Dz7a87ThGIqgdCZ2zpQy33a0SVNMfmJLSNnDzJ71TU68Rc-3PKE7VA3kYzjk4RrKU";

        /**
         * 思路：
         * 1、先确定 url 的开始部分 https:// | http://  ((http|https)://)
         * 2、确定域名的部分 ([\w-]+\.)+[\w-]+
         * 3、匹配域名后面的路径和参数  (\\/[\\w-?=&/%.#]*)?
         */
        String regStr = "((http|https)://)?([\\w-]+\\.)+[\\w-]+(\\/[\\w-?=&/%.#]*)?"; //注意：[.]表示匹配就是 . 本身

        Pattern pattern = Pattern.compile(regStr);

        Matcher matcher = pattern.matcher(content);

        if (matcher.find()) {

            System.out.println("满足格式");

        } else {

            System.out.println("不满足格式");

        }

        System.out.println("是否整体匹配:" + Pattern.matches(regStr, content));

    }

}
</syntaxhighlight><syntaxhighlight lang="console">
满足格式
是否整体匹配:true
</syntaxhighlight>





==== 示例5： ====
<syntaxhighlight lang="java">
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RegExp11 {

    public static void main(String[] args) {

        String content = "010http://edu.3dsmax.tech/yg/bitibiti/my6652/pc/qg/05-51/index.html#201211-1?track_id=jMc0jn-hm-yHrNfVad37YdhOUh41XYmjlss9zocM26gspY5ArwWuxb4wYWpmh2Q7doU0wLkViEhUIO1qNtukyAgake2jG1bTd23IR57XzV83E9bAXWkStcAh4j9Dz7a87ThGIqgdCZ2zpQy33a0SVNMfmJLSNnDzJ71TU68Rc-3PKE7VA3kYzjk4RrKU";

        /**
         * 思路：
         * 1、先确定 url 的开始部分 https:// | http://  ((http|https)://)
         * 2、确定域名的部分 ([\w-]+\.)+[\w-]+
         * 3、匹配域名后面的路径和参数  (\\/[\\w-?=&/%.#]*)?
         */
        String regStr = "((http|https)://)?([\\w-]+\\.)+[\\w-]+(\\/[\\w-?=&/%.#]*)?"; //注意：[.]表示匹配就是 . 本身

        Pattern pattern = Pattern.compile(regStr);

        Matcher matcher = pattern.matcher(content);

        if (matcher.find()) {

            System.out.println("满足格式");

        } else {

            System.out.println("不满足格式");

        }

        System.out.println("是否整体匹配:" + Pattern.matches(regStr, content));

    }

}
</syntaxhighlight><syntaxhighlight lang="console">
满足格式
是否整体匹配:false
</syntaxhighlight>


==== 示例6： ====
<syntaxhighlight lang="java">
import java.util.regex.Pattern;

public class Hello {
    public static void main(String[] args) {

        String content = "I am hsp from hspedu.com.";
        String pattern = ".*hspedu.*";
        boolean isMatch = Pattern.matches(pattern, content);
        System.out.println("是否整体匹配成功：" + isMatch);

    }
}
</syntaxhighlight><syntaxhighlight lang="console">
是否整体匹配成功：true
</syntaxhighlight>





=== 源码： ===
<syntaxhighlight lang="java">
package java.util.regex;    

……
public final class Pattern
    implements java.io.Serializable
{
……
    public static boolean matches(String regex, CharSequence input) {
        Pattern p = Pattern.compile(regex);
        Matcher m = p.matcher(input);
        return m.matches();
    }
……
}
</syntaxhighlight>