Give more detail when a JSON schema triggers parse exception

[joelittlejohn]

Original author: PaulGr...@gmail.com (May 30, 2012 20:10:12)

What steps will reproduce the problem?

1. Use an invalid schema. This one is missing a comma after ("id": "Market"):

{
"description": "An object describing a betting market for a match",
"type": "object",
"id": "Market"
"properties": {
"name": {
"type": "string"
},
"handicap": {
"type": "string"
},
"odds": {
"type": "string"
},
"bookmaker": {
"type": "string"
}
}
}

1. Try and generate.
2. Get com.fasterxml.jackson.core.JsonParseException.

What is the expected output?

An exception is thrown, but it doesn't tell you which of your schema files is at fault:

Preparing to Execute Maven in Debug Mode
Listening for transport dt_socket at address: 8000
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Building Unnamed - xxx.xxx:xxx:war:0.0.1-SNAPSHOT
[INFO] task-segment: [compile]
[INFO] ------------------------------------------------------------------------
[INFO] [jsonschema2pojo:generate {execution: default}]
[INFO] ------------------------------------------------------------------------
[ERROR] FATAL ERROR
[INFO] ------------------------------------------------------------------------
[INFO] com.fasterxml.jackson.core.JsonParseException: Unexpected character ('"' (code 34)): was expecting comma to separate OBJECT entries
at [Source: java.io.BufferedInputStream@ed8eb5; line: 5, column: 6]
[INFO] ------------------------------------------------------------------------
[INFO] Trace
com.googlecode.jsonschema2pojo.exception.GenerationException: com.fasterxml.jackson.core.JsonParseException: Unexpected character ('"' (code 34)): was expecting comma to separate OBJECT entries
at [Source: java.io.BufferedInputStream@ed8eb5; line: 5, column: 6]
at com.googlecode.jsonschema2pojo.Schema.create(Schema.java:73)
at com.googlecode.jsonschema2pojo.Schema.create(Schema.java:104)
at com.googlecode.jsonschema2pojo.rules.JsonSchemaRule.apply(JsonSchemaRule.java:59)
at com.googlecode.jsonschema2pojo.rules.JsonSchemaRule.apply(JsonSchemaRule.java:30)
at com.googlecode.jsonschema2pojo.SchemaMapperImpl.generate(SchemaMapperImpl.java:65)
at com.googlecode.jsonschema2pojo.cli.Jsonschema2Pojo.generate(Jsonschema2Pojo.java:88)
at com.googlecode.jsonschema2pojo.maven.Jsonschema2PojoMojo.execute(Jsonschema2PojoMojo.java:172)
at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:490)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:694)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalWithLifecycle(DefaultLifecycleExecutor.java:556)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:535)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:387)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:348)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:180)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:362)
at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:60)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
at org.codehaus.classworlds.Launcher.main(Launcher.java:375)
Caused by: com.fasterxml.jackson.core.JsonParseException: Unexpected character ('"' (code 34)): was expecting comma to separate OBJECT entries
at [Source: java.io.BufferedInputStream@ed8eb5; line: 5, column: 6]
at com.fasterxml.jackson.core.JsonParser._constructError(JsonParser.java:1274)
at com.fasterxml.jackson.core.base.ParserMinimalBase._reportError(ParserMinimalBase.java:588)
at com.fasterxml.jackson.core.base.ParserMinimalBase._reportUnexpectedChar(ParserMinimalBase.java:509)
at com.fasterxml.jackson.core.json.UTF8StreamJsonParser.nextToken(UTF8StreamJsonParser.java:488)
at com.fasterxml.jackson.databind.deser.std.BaseNodeDeserializer.deserializeObject(JsonNodeDeserializer.java:192)
at com.fasterxml.jackson.databind.deser.std.JsonNodeDeserializer.deserialize(JsonNodeDeserializer.java:58)
at com.fasterxml.jackson.databind.deser.std.JsonNodeDeserializer.deserialize(JsonNodeDeserializer.java:15)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:2563)
at com.fasterxml.jackson.databind.ObjectMapper.readTree(ObjectMapper.java:1500)
at com.googlecode.jsonschema2pojo.Schema.create(Schema.java:65)
... 25 more
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 5 minutes 3 seconds
[INFO] Finished at: Wed May 30 21:00:03 BST 2012
[INFO] Final Memory: 7M/19M
[INFO] ------------------------------------------------------------------------

Suggestion

In com.googlecode.jsonschema2pojo.Schema.create(java.net.URI) line: 73

we have the URI available. Use that in the exception for more information. E.g.:

throw new GenerationException("Error with schema: " + id, e);

This change requires a new constructor in com.googlecode.jsonschema2pojo.exception.GenerationException.

public GenerationException(String message, Throwable cause) {
    super(message, cause);
}

What version of the product are you using? On what Java version?

0.2.5-SNAPSHOT (Rev 104770c)

java version "1.6.0_31"

Original issue: http://code.google.com/p/jsonschema2pojo/issues/detail?id=51

[joelittlejohn]

This issue is a duplicate of #50