Java Database Connectivity (JDBC)

I am getting below error once in a while:

java.sql.SQLException: Cannot map Unicode to Oracle character.
at oracle.sql.converter.CharacterConverter1Byte.toOracleCharacter(CharacterConverter1Byte.java:156)
at oracle.sql.converter.CharacterConverter1Byte.toOracleString(CharacterConverter1Byte.java:246)
at oracle.sql.CharacterSetWithConverter.convert(CharacterSetWithConverter.java:160)
at oracle.sql.CHAR.<init>(CHAR.java:133)
at oracle.sql.CHAR.<init>(CHAR.java:157)
at oracle.jdbc.oracore.OracleTypeCHAR.toDatum(OracleTypeCHAR.java:145)
at oracle.sql.StructDescriptor.toOracleArray(StructDescriptor.java:438)
at oracle.sql.StructDescriptor.toArray(StructDescriptor.java:839)
at oracle.sql.STRUCT.<init>(STRUCT.java:121)
at oracle.sql.OracleSQLOutput.getSTRUCT(OracleSQLOutput.java:96)
at oracle.sql.STRUCT.toSTRUCT(STRUCT.java:408)
at oracle.jdbc.oracore.OracleTypeADT.toDatum(OracleTypeADT.java:284)
at oracle.jdbc.oracore.OracleTypeADT.toDatumArray(OracleTypeADT.java:327)
at oracle.jdbc.oracore.OracleTypeUPT.toDatumArray(OracleTypeUPT.java:143)
at oracle.sql.ArrayDescriptor.toOracleArray(ArrayDescriptor.java:771)
at oracle.sql.ARRAY.<init>(ARRAY.java:118)


Code:

ArrayDescriptor desc = ArrayDescriptor.createDescriptor(tableArray, conn);
ARRAY array = new ARRAY(desc, conn, listNArray);

I am not able to figure out what that character would be? I am not using any XML or...

Using Oracle 9i.