Java 从字符串中提取变量值

鉴于用户只能以特定格式输入值，我需要将该字符串的相关部分提取到Java变量中

例如，可以接受的格式有：-

String types[] = {"The quick brown ${animal} jumped over the lazy ${target}.",
                  "${target} loves ${animal}.",
                  "${animal} became friends with ${target}"};

变量：-

private String animal;
private String target;

现在，如果用户输入快速棕色狐狸跳过懒惰的狗，则动物变量应设置为fox，目标变量应设置为dog

如果用户输入与任何给定类型都不匹配，则应显示错误

基本上，我正试图做org.apache.commons.lang.text.StrSubstitutor所做的相反的事情

我的方法看起来效率低下，因此请求帮助：-

---

创建正则表达式模式，找出输入字符串的类型，然后为每个类型编写不同的逻辑。例如，对于第一种类型，在单词brown之后获取单词并将其分配给variable animal，依此类推。

您可以使用命名的捕获组执行此操作：

String userInput = "dog loves fox.";

String types[] = {"The quick brown (?<animal>.*?) jumped over the lazy (?<target>.*?).",
                  "(?<target>.*?) loves (?<animal>.*?).",
                  "(?<animal>.*?) became friends with (?<target>.*?)"};

Matcher m;

for(int i=0; i<types.length(); i++;){
    if(userInput.matches(types[i]){
        m = Pattern.compile(types[i]).matcher(userInput);
        break;
    }
}

m.find();

String animal = m.group("animal");
String target = m.group("target");

使用@Josh Withee的：-

测试：-

    @Test
    public void shouldExtractVariablesFromString() {
        String input = "The quick brown fox jumped over the lazy dog.";
        String types[] = {"The quick brown (?<animal>.*) jumped over the lazy (?<target>.*).",
                "(?<target>.*) loves (?<animal>.*).",
                "(?<animal>.*) became friends with (?<target>.*)"};
        Map<String, String> resultMap = StringUtils.extractVariablesFromString(input, Arrays.asList(types), "animal", "target1", "target");
        Assert.assertEquals("fox", resultMap.get("animal"));
        Assert.assertEquals("dog", resultMap.get("target"));
        Assert.assertFalse(resultMap.containsKey("target1"));
    }

    @Test
    public void shouldReturnEmptyMapIfInputDoesntMatchAnyPatternForVariableExtraction() {
        String input = "The brown fox passed under the lazy dog.";
        String types[] = {"The quick brown (?<animal>.*) jumped over the lazy (?<target>.*).",
                "(?<animal>.*) became friends with (?<target>.*)"};
        Map<String, String> resultMap = StringUtils.extractVariablesFromString(input, Arrays.asList(types), "animal", "target1", "target");
        Assert.assertTrue(resultMap.isEmpty());
    }

---

在一个罕见的例子中，我实际上发现了一篇与您的问题完全相同的Code Ranch文章：只需根据您的问题调整代码样本。@TimBiegeleisen这是一个不同的问题，我不认为简单地使用appendReplacement就可以解决它，appendReplacement提供字符串的匹配部分。Map valuesMap=new HashMap；动物，敏捷的棕色狐狸；valuesMap.puttarget，懒狗；String templateString=${animal}跳过了${target}。；StrSubstitutor sub=新的StrSubstitutorvaluesMap；String resolvedString=sub.replacetemplateString；谢谢马拉松55。我必须搬走吗？从命名组的末尾开始使其工作。比如？*？已更改为？*。我添加了一个答案，试图将其转换为Java8。还有，有没有什么方法可以让我不必提供动物和目标这样的名称，而仍然可以得到一张地图，上面有它找到的所有命名组？i、 在我的回答中，我不想在参数中提供variableNames。你可以随意命名命名的捕获组。很明显，它们不必与变量同名。我的意思是，与在m.groupanimal中按名称请求组不同，有没有一种方法可以不指定组的名称并获取所有组？类似于m.getAllGroups，它将返回一个映射，其中组名作为键，实际值作为映射值？如果没有办法，这也行。谢谢

    @Test
    public void shouldExtractVariablesFromString() {
        String input = "The quick brown fox jumped over the lazy dog.";
        String types[] = {"The quick brown (?<animal>.*) jumped over the lazy (?<target>.*).",
                "(?<target>.*) loves (?<animal>.*).",
                "(?<animal>.*) became friends with (?<target>.*)"};
        Map<String, String> resultMap = StringUtils.extractVariablesFromString(input, Arrays.asList(types), "animal", "target1", "target");
        Assert.assertEquals("fox", resultMap.get("animal"));
        Assert.assertEquals("dog", resultMap.get("target"));
        Assert.assertFalse(resultMap.containsKey("target1"));
    }

    @Test
    public void shouldReturnEmptyMapIfInputDoesntMatchAnyPatternForVariableExtraction() {
        String input = "The brown fox passed under the lazy dog.";
        String types[] = {"The quick brown (?<animal>.*) jumped over the lazy (?<target>.*).",
                "(?<animal>.*) became friends with (?<target>.*)"};
        Map<String, String> resultMap = StringUtils.extractVariablesFromString(input, Arrays.asList(types), "animal", "target1", "target");
        Assert.assertTrue(resultMap.isEmpty());
    }