使用递归创建深度嵌套的JSON

Question

This JSON is the output that I am expecting,

    [{
    "text": "a",
    "nodes": [{
        "text": "aa",
        "nodes": [{
            "text": "aa1"
        }, {
            "text": "aa2",
            "nodes": [{
                    "text": "aaa1"
                },
                {
                    "text": "aaa2",
                    "nodes": [{
                        "text": "aaaa21"
                    }]
                },
                {
                    "text": "aaa3"
                }
            ]
        }]
    }]
},
{
    "text": "b",
    "nodes": [{
            "text": "bb1"
        },
        {
            "text": "bb2"
        }
    ]
},
{
    "text": "c",
    "nodes": [{
        "text": "cc"
    }]
},
{
    "text": "d",
    "nodes": [{
        "text": "dd1",
        "nodes": [{
                "text": "ddd1"
            },
            {
                "text": "ddd2"
            },
            {
                "text": "ddd3",
                "nodes": [{
                    "text": "ddd31",
                    "nodes": [{
                        "text": "ddd32"
                    }]
                }]
            }
        ]
    }]
}]

So to in short from the below table structure I want to generate a JSON tree like above, Please someone share me a java code/Algorithm for this..

A simple recursion method would help me, Or Is there any standard library to do this

Answer 1

Your immediate problem is that your recursive function executes the SQL query each time it is called and so never gets beyond the first result row. Hence the stack overflow. Re-structure your code so that the query is executed just once at the beginning. I haven't got time to set up a table to try this out, but intuitively, you need to move the function to start just before the 'while' loop.