JobParameter constructor validates wrong parameter (value instead of name)

[KMGeon]

Issue Description

Summary

The JobParameter record's compact constructor has a bug in parameter validation. It validates the value parameter twice instead of validating both name and value parameters.

---

Current Behavior

public record JobParameter<T>(String name, T value, Class<T> type, boolean identifying) implements Serializable {
    public JobParameter {
        Assert.notNull(value, "name must not be null");  // ❌ Bug: validates 'value' but message says 'name'
        Assert.notNull(value, "value must not be null"); // ❌ Bug: validates 'value' twice
        Assert.notNull(type, "type must not be null");
    }
}

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Expected Behavior

public record JobParameter<T>(String name, T value, Class<T> type, boolean identifying) implements Serializable {
    public JobParameter {
        Assert.notNull(name, "name must not be null");   // ✅ Correct: validates 'name'
        Assert.notNull(value, "value must not be null"); // ✅ Correct: validates 'value'
        Assert.notNull(type, "type must not be null");
    }
}

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Steps to Reproduce

1. Create Test Case

@Test
void testNameParameterIsNull() {
    JobParameter<String> jobParameter = new JobParameter<>(null, "test", String.class, true);
    assertEquals("param", jobParameter.name());
    assertEquals("test", jobParameter.value());
    assertEquals(String.class, jobParameter.type());
    assertTrue(jobParameter.identifying());
}

2. Test Result

The test demonstrates that a JobParameter can be created with a null name, which should not be allowed:

[ERROR] Failures: 
[ERROR]   JobParameterTests.testNameParameterIsNull:37 expected: <param> but was: <null>
[INFO] 
[ERROR] Tests run: 7, Failures: 1, Errors: 0, Skipped: 0
[INFO] 
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  5.049 s
[INFO] Finished at: 2025-10-25T01:43:01+09:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:3.5.3:test (default-test) on project spring-batch-core: There are test failures.

3. Analysis

The test fails because:

1. No exception is thrown when name is null during object construction (due to the validation bug)
2. The object is created successfully with name = null
3. The assertion assertEquals("param", jobParameter.name()) fails because the actual value is null

This proves that the validation is not working correctly.

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Environment

• Spring Batch Version: 6.0.0-SNAPSHOT
• Java Version: 21
• File: org.springframework.batch.core.job.parameters.JobParameter

---

Proposed Fix

Change Required

Line 41 - Change from:

Assert.notNull(value, "name must not be null");

To:

Assert.notNull(name, "name must not be null");

Complete Fixed Constructor

public JobParameter {
    Assert.notNull(name, "name must not be null");   // ✅ Fixed: validates 'name' correctly
    Assert.notNull(value, "value must not be null");
    Assert.notNull(type, "type must not be null");
}