json - Java + jackson parsing error Unrecognized character escape -

i need post json string , using httpclient. following code have. other end json mapped object.

httpclient client = httpclientbuilder.create().build(); httppost post = new httppost(url); string jsondata = "{ \"provider\" : null , \"password\" : \"a\", \"userid\" : \"mlpdemo\\mlpdemoins\" }"; post.setentity(new bytearrayentity(         jsondata.tostring().getbytes("utf8"))); httpresponse response = client.execute(post); 

here others correctly mapping expect userid. here problem backward slash(mlpdemo\mlpdemins). guess. if send single string user id mapped without issues. eg:-

string jsondata = "{ \"provider\" : null , \"password\" : \"a\", \"userid\" : \"mlpdemoins\" }"; 

this works .

but need (mlpdemo\mlpdemins)to sent through post. please me out.

string jsondata = "{ \"provider\" : null , \"password\" : \"a\", \"userid\" : \"mlpdemo\\mlpdemoins\" }"; 

here exception im getting.

com.fasterxml.jackson.core.jsonparseexception: unrecognized character escape 'm' (code 109)  @ [source: java.io.inputstreamreader@29f0a0a2; line: 1, column: 62] badrequestexception (0ea35150-f33a-4932-a31e-8a1048af53ad): 400 bad request, com.strategicgains.restexpress.serialization.deserializationexception: com.fasterxml.jackson.core.jsonparseexception: unrecognized character escape 'm' (code 109)  @ [source: java.io.inputstreamreader@29f0a0a2; line: 1, column: 62]     @ com.strategicgains.restexpress.request.getbodyas(request.java:165)     @ com.strategicgains.restexpress.request.getbodyas(request.java:181) 

mlpdemo\mlpdemoins invalid string can't use in json . can use mlpdemo\\mlpdemoins easily.

below code works fine me :

string jsondata = "{ \"provider\" : null , \"password\" : \"a\", \"userid\" : \"mlpdemo\\\\mlpdemoins\" }";  objectmapper mapper=new objectmapper();  system.out.println(mapper.readtree(jsondata)); 

it produce output json :

{"provider":null,"password":"a","userid":"mlpdemo\\mlpdemoins"}