IllegalArgumentException:RestTemplate 没有足够的变量值可用

Question

我正在尝试使用RestTemplate执行URL，如下所示 -

public static void main(String[] args) throws UnsupportedEncodingException {
    RestTemplate restTemplate = new RestTemplate();
    String url = "http://ptr.vip.host.com/pss/repositories/pssdb/branches/main/query/Service[@alias="
                        + "hello"
                        + "].serviceInstances.runsOn{@resourceId}?allowScan=true&limit=10000&skip=0";
    try {
        String response = restTemplate.getForObject(url, String.class);
        System.out.println(response);
    } catch (RestClientException ex) {
        ex.printStackTrace();
    }
}

但每次我遇到这样的错误时——

Exception in thread "main" java.lang.IllegalArgumentException: Not enough variable values available to expand '@resourceId'
    at org.springframework.web.util.UriComponents$VarArgsTemplateVariables.getValue(UriComponents.java:272)

我做错了什么以及如何解决？

更新：-

我也尝试使用此网址，但它对我不起作用。我只是用{{@resourceId}}替换了{@resourceId}

String url = "http://ptr.vip.host.com/pss/repositories/pssdb/branches/main/query/Service[@alias="
                        + "hello"
                        + "].serviceInstances.runsOn{{@resourceId}}?allowScan=true&limit=10000&skip=0";

更新-2

这是代码 -

try {
    UriComponentsBuilder builder = UriComponentsBuilder
            .fromPath("http://ptr.vip.str.host.com/pss/repositories/pssdb/branches/main/query/Service[@alias="
                    + "hello"
                    + "].serviceInstances.runsOn{@resourceId}?allowScan=true&limit=10000&skip=0");
    UriComponents uriComponents = builder.build();
    URI uri = uriComponents.toUri();
    String response = restTemplate.getForObject(uri, String.class);
    System.out.println(response);
} catch (RestClientException ex) {
    ex.printStackTrace();
}

错误是——

Exception in thread "main" java.lang.IllegalArgumentException: URI is not absolute
    at java.net.URI.toURL(URI.java:1095)
    at org.springframework.http.client.SimpleClientHttpRequestFactory.createRequest(SimpleClientHttpRequestFactory.java:109)
    at org.springframework.http.client.support.HttpAccessor.createRequest(HttpAccessor.java:76)
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:479)
    at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:460)
    at org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:228)

Answer 1

似乎RestTemplate没有办法忽略{...}.相反，请从String值生成URI(不带双{}(。

String url = "http://ptr.vip.host.com/pss/repositories/pssdb/branches/main/query/Service[@alias="
            + "hello"
            + "].serviceInstances.runsOn{@resourceId}?allowScan=true&limit=10000&skip=0";
UriComponentsBuilder builder = UriComponentsBuilder.fromPath(url);
UriComponents uriComponents = builder.build();
URI uri = uriComponents.toUri();

并使用需要URI的重载getForObject方法。

Answer 2

U 应该看到 RestTemplate 的搜索结果。getForObject 的方法需要三个参数，例如

public <T> T getForObject(String url, Class<T> responseType, Object... urlVariables)

"url

"是url前缀的一部分(在"？"前面(，"urlVariables"是一个参数数组。