A DESCRIPTION OF THE PROBLEM :
The test failed with StringIndexOutOfBoundsException because you didn't judge the length before calling substring method.

ACTUAL -
java.lang.StringIndexOutOfBoundsException: String index out of range: -1

at java.lang.String.substring(String.java:1927)
at javax.sql.rowset.serial.SerialClob.setString(SerialClob.java:408)

---------- BEGIN SOURCE ----------
    @Test
    public void test_setString_119_125() throws java.sql.SQLException{
        long long1 = -1L;
        String string2 = "{\"key\":null}";
        int int3 = -1;
        int int4 = -1;
        char[] charArray5 = {'\''};
        javax.sql.rowset.serial.SerialClob serialClob0 = new javax.sql.rowset.serial.SerialClob(charArray5);
        serialClob0.setString(long1, string2, int3, int4);
    }
---------- END SOURCE ----------