我正在使用一个 URL 访问 REST API，该 URL 给出了以下 JSON 结果:

{"size":1,"filter":{"applicationName":"xx.x1",
"fromTimestamp":1261746800000,
"toTimestamp":1361833200000,
"company":"xx",
"groupedBy":"COMPANY_APPLICATION"},

"values"[{"applicationName":"xx.x1","count":17,"company":"xx"}],
"start":0,"limit":25,"lastPage":true} 

我尝试使用 Jackson 以这种方式解析 json:

          ObjectMapper mapper = new ObjectMapper(); 

      try {
        ErrorDataRest error = mapper.readValue(url, ErrorDataRest.class);
        Map<String,Object> map = mapper.readValue(url, Map.class);

不管我使用第一个还是第二个，我都会得到这个异常:

dk.jyskebank.jee.core.exception.JyskeSystemException: Auto generated exception
at dk.sd.dumpmonitor.domainservice.RestErrorServiceBean.queryRESTurl(RestErrorServiceBean.java:46)
at service.RestErrorServiceTest.testQueryRESTurl(RestErrorServiceTest.java:19)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: org.codehaus.jackson.JsonParseException: Unexpected character ('h' (code 104)): expected a valid value (number, String, array, object, 'true', 'false' or 'null')
at [Source: java.io.StringReader@30d82d; line: 1, column: 2]
at org.codehaus.jackson.JsonParser._constructError(JsonParser.java:1433)
at org.codehaus.jackson.impl.JsonParserMinimalBase._reportError(JsonParserMinimalBase.java:521)
at org.codehaus.jackson.impl.JsonParserMinimalBase._reportUnexpectedChar(JsonParserMinimalBase.java:442)
at org.codehaus.jackson.impl.ReaderBasedParser._handleUnexpectedValue(ReaderBasedParser.java:1198)
at org.codehaus.jackson.impl.ReaderBasedParser.nextToken(ReaderBasedParser.java:485)
at org.codehaus.jackson.map.ObjectMapper._initForReading(ObjectMapper.java:2770)
at org.codehaus.jackson.map.ObjectMapper._readMapAndClose(ObjectMapper.java:2718)
at org.codehaus.jackson.map.ObjectMapper.readValue(ObjectMapper.java:1863)
at dk.sd.dumpmonitor.domainservice.RestErrorServiceBean.queryRESTurl(RestErrorServiceBean.java:43)
... 25 more

我不知道哪里出了问题或如何解决。

我无法访问其余 API，但我知道它使用 RESTeasy。

我唯一想要的是将 JSON 响应映射到 Java 类，所以也许还有其他方法可以做到这一点？

最佳答案

我猜你的变量 url 是一个 String，而不是一个 URL，所以 Jackson 解析 URL 就好像它是一个实际的 JSON 字符串。这将解释“意外字符‘h’”，因为它可能是您 URL 的第一个字母(即 http... 某物。)代码“104”对应于“h”的 ASCII 值。

如果你使用 mapper.readValue(new URL(url), ErrorDataRest.class); 它有效吗？

关于java - Jackson 意外字符 ('h'(代码 104)) : expected a valid value，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15885544/