setEmail(java.lang.String)' on a null object reference

Question

Could someone help me correct this error, thank you in advance. I have been trying to correct for a while but I am unsuccessful in my attempts.

I don't see an error in the code when registering it works well, it is redirected to main activity but when I go out and try to login, this error described below occurs.

Any help is welcome. I'm getting this error

java.lang.NullPointerException: Attempt to invoke virtual method 'void myapp.COM.model.Usuario.setEmail(java.lang.String)' on a null object reference
        at myapp.COM.activity.LoginActivity$1.onClick(LoginActivity.java:54)

Login code:

//Fazer login do usuario
        progressBar.setVisibility( View.GONE );
        botaoEntrar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                String textoEmail = campoEmail.getText().toString();
                String textosenha = campoSenha.getText().toString();

                if( !textoEmail.isEmpty() ){
                    if( !textosenha.isEmpty() ){


                        usuario.setEmail( textoEmail );
                        usuario.setSenha( textosenha );
                        validarLogin( usuario );

                    }else{
                        Toast.makeText(LoginActivity.this,
                                "Preencha a senha!",
                                Toast.LENGTH_SHORT).show();
                    }
                }else{
                    Toast.makeText(LoginActivity.this,
                            "Preencha o e-mail!",
                            Toast.LENGTH_SHORT).show();
                }

            }
        });

Model Usuario

public class Usuario implements Serializable {

    private String id;
    private String nome;
    private String email;
    private String senha;
    private String caminhoFoto;
    private int seguidores = 0;
    private int seguindo = 0;
    private int postagens = 0;
    private String money;
    private String cassinotime;
    private  String cassinoprofit;

    public String getMoney() {
        return money;
    }

    public void setMoney(String money) {
        this.money = money;
    }

    public String getCassinotime() {
        return cassinotime;
    }

    public void setCassinotime(String cassinotime) {
        this.cassinotime = cassinotime;
    }

    public String getCassinoprofit() {
        return cassinoprofit;
    }

    public void setCassinoprofit(String cassinoprofit) {
        this.cassinoprofit = cassinoprofit;
    }

    public Usuario() {
    }

    public void salvar(){
        DatabaseReference firebaseRef = ConfiguracaoFirebase.getFirebase();
        DatabaseReference usuariosRef = firebaseRef.child("usuarios").child( getId() );
        usuariosRef.setValue( this );
    }

    public void atualizarQtdPostagem(){

        DatabaseReference firebaseRef = ConfiguracaoFirebase.getFirebase();
        DatabaseReference usuariosRef = firebaseRef
                .child("usuarios")
                .child( getId() );

        HashMap<String, Object> dados = new HashMap<>();
        dados.put("postagens", getPostagens() );

        usuariosRef.updateChildren( dados );

    }

    public void atualizar(){

        DatabaseReference firebaseRef = ConfiguracaoFirebase.getFirebase();

        Map objeto = new HashMap();
        objeto.put("/usuarios/" + getId() + "/nome", getNome() );
        objeto.put("/usuarios/" + getId() + "/caminhoFoto", getCaminhoFoto() );

        firebaseRef.updateChildren( objeto );

    }

    public Map<String, Object> converterParaMap(){

        HashMap<String, Object> usuarioMap = new HashMap<>();
        usuarioMap.put("email", getEmail() );
        usuarioMap.put("nome", getNome() );
        usuarioMap.put("id", getId() );
        usuarioMap.put("caminhoFoto", getCaminhoFoto() );
        usuarioMap.put("seguidores", getSeguidores() );
        usuarioMap.put("seguindo", getSeguindo() );
        usuarioMap.put("postagens", getPostagens() );

        return usuarioMap;

    }

    public int getSeguidores() {
        return seguidores;
    }

    public void setSeguidores(int seguidores) {
        this.seguidores = seguidores;
    }

    public int getSeguindo() {
        return seguindo;
    }

    public void setSeguindo(int seguindo) {
        this.seguindo = seguindo;
    }

    public int getPostagens() {
        return postagens;
    }

    public void setPostagens(int postagens) {
        this.postagens = postagens;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getNome() {
        return nome;
    }

    public void setNome(String nome) {
        this.nome = nome.toUpperCase();
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    @Exclude
    public String getSenha() {
        return senha;
    }

    public void setSenha(String senha) {
        this.senha = senha;
    }

    public String getCaminhoFoto() {
        return caminhoFoto;
    }

    public void setCaminhoFoto(String caminhoFoto) {
        this.caminhoFoto = caminhoFoto;
    }
}

Answer 1

You need to create the object of Usuario class before setting attributes to the object of Usuario.

Please try below:

botaoEntrar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Usuario usuario = new Usuario();
                String textoEmail = campoEmail.getText().toString();
                String textosenha = campoSenha.getText().toString();

                if( !textoEmail.isEmpty() ){
                    if( !textosenha.isEmpty() ){


                        usuario.setEmail( textoEmail );
                        usuario.setSenha( textosenha );
                        validarLogin( usuario );

                    }else{
                        Toast.makeText(LoginActivity.this,
                                "Preencha a senha!",
                                Toast.LENGTH_SHORT).show();
                    }
                }else{
                    Toast.makeText(LoginActivity.this,
                            "Preencha o e-mail!",
                            Toast.LENGTH_SHORT).show();
                }

            }
        });