http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Bjml%
} 8H./@~_ =
for(int i=0;i<nEndPos.length-1;i++) Ox?LVRvxI
{ E87/B%R
nEndPos = nStartPos[i+1]; cx|[P6d
} !s.G$ JS<
nEndPos[nEndPos.length-1] = nFileLength; w4'(Y,(`
} Yk(OVl T
} Xx:0Nt]
>r{3t{
d%1S6eYa'
//启动子线程 ?Ee?Ol?i2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _S8]W !c
for(int i=0;i<nStartPos.length;i++) Il2DZ5- )
{ ,Ot3N\%yn
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H`-%)c=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), BT 98WR"\
nStartPos,nEndPos,i); t"2WJ-1k}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bVtboHlY
fileSplitterFetch.start(); l6xC'c,jg
} =ADAMP
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I m_yY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m{mK;D
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", + h`:qB
nEndPos = " + nFileLength); yZxgUF&`
// fileSplitterFetch[nPos.length-1].start(); wz.Il-sm
4I"QT(;
EYGJDv(S
//等待子线程结束 TnL%_!V!
//int count = 0; fB1JU1
//是否结束while循环 miuJ!Kr'
boolean breakWhile = false; ]j*o&6cQf
AbZ:AJ(
X^_,`H@
while(!bStop) eWqJ2Tt
{ bsM`C]h&
write_nPos(); Br]VCp
Utility.sleep(500); LAwX9q`
breakWhile = true; BRQ9kK20
PHfGl
aC]~
for(int i=0;i<nStartPos.length;i++) ?P<&8eY
{ rMe`HM@
if(!fileSplitterFetch.bDownOver) (S5'iksx
{ }w8h^(+B
breakWhile = false; }O2hhh_
break; |1g2\5Re
} g.DgJX&i
} %!(6vm>8
if(breakWhile) U~Ni2|}\C9
break; L$ ]D&f8:
uAzVa!)
t1Hd-]28V
//count++; J9/9k
//if(count>4) s]L`&fY]O
// siteStop(); ?U|~h1
} Se"\PxBR
IZJV6clM
rM[Ps=5
System.err.println("文件下载结束！"); *Ei~2O}
} |YZ`CN<
catch(Exception e){e.printStackTrace ();} F!pUfF,&
} {zbH.V[
i`2Q;Az_P6
?aSL'GI
//获得文件长度 Lrq+0dI 65
public long getFileSize() VxjHB?)
{ &9o @x]) @
int nFileLength = -1; 8C,?Ai<ro
try{ "kP.Kx!
URL url = new URL(siteInfoBean.getSSiteURL()); L2{tof
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @#VxjXW^
httpConnection.setRequestProperty("User-Agent","NetFox"); M*t@Q|$:
E'XFn'
2(\>PN-
int responseCode=httpConnection.getResponseCode(); &JfyXM[]
if(responseCode>=400) mWmDH74
{ Pl1:d{"d
processErrorCode(responseCode); `E!t,*(*E
return -2; //-2 represent access is error r}f-.Fo
} 5 Nl>4d`
,:>>04O
g'pE z
String sHeader; =C`v+NPM)|
rZJp>Q)s
G9E?
for(int i=1;;i++) E'MMhlo
{ N_C\L2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \hi{r@k>}
//Utility.log(in.readLine()); v{JCEb&wN
sHeader=httpConnection.getHeaderFieldKey(i); .]r[0U
if(sHeader!=null) _ esFx
{ /^#} \<;
if(sHeader.equals("Content-Length")) QR4v6*VpD
{ CXUNdB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >#!n"i;
break; E8%O+x}
} _$cQAH0 E
} 1-w1k^e
else #7Qn\C2
break; ]t(g7lc}U
} /&kZ)XOi
} (6 0,0|s
catch(IOException e){e.printStackTrace ();} ?_HTOOa
catch(Exception e){e.printStackTrace ();} !o*oT}6n
j:<E=[Kl
4+v~{
Utility.log(nFileLength); %#7M~RB[
1ed#nB%
j1/J9F'
return nFileLength; 3kKXzIh
} -MB,]m
x!I7vs~~zW
|2n2
//保存下载信息（文件指针位置） >{m>&u;Cc
private void write_nPos() {tWfLfzU
{ /eIwv31
try{ l l&iMj]
output = new DataOutputStream(new FileOutputStream(tmpFile)); WU=Os8gR
output.writeInt(nStartPos.length); h!d#=.R
for(int i=0;i<nStartPos.length;i++) _e`b^_
{ 0CTI=<;
// output.writeLong(nPos); VJ;'$SYx
output.writeLong(fileSplitterFetch.nStartPos); u=ENf1{ $>
output.writeLong(fileSplitterFetch.nEndPos); o &Nr5S
} ty-4yK#
output.close(); 4{fi=BA
} , / 4}CM
catch(IOException e){e.printStackTrace ();} s[xdID^3.
catch(Exception e){e.printStackTrace ();} Bb-x1{t
} ,{E'k+
tM@TT@.t~
pdtK3Pf
//读取保存的下载信息（文件指针位置） N4HnW0
private void read_nPos() q=96Ci_a
{ Zqx5I~
try{ w7dG=a&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); V]vk9M2q[l
int nCount = input.readInt(); `^_.E:f
nStartPos = new long[nCount]; A;2?!i#f
nEndPos = new long[nCount]; :=~([oSNW"
for(int i=0;i<nStartPos.length;i++) r-'j#|^tz
{ Cs*u{O
nStartPos = input.readLong(); {BKI8vy
nEndPos = input.readLong(); :j9;P7&"?
} qPzgGbmD9
input.close(); *B3` #t
} \J1Jn~
catch(IOException e){e.printStackTrace ();} [8)Zhw$
catch(Exception e){e.printStackTrace ();} DM>j@(uWF
} XqJ@NgsY
C/]0jAAE7
["@K~my~D*
private void processErrorCode(int nErrorCode) lHP[WO
{ "G4{;!0C
System.err.println("Error Code : " + nErrorCode); 1h)I&T"kZ
} Gc SX5c
4|Z3;;%+
C:P,q6
//停止文件下载 CZbp}:|
public void siteStop() :L\@+}{(c
{ bLf }U9
bStop = true; D$ `yxc
for(int i=0;i<nStartPos.length;i++) M4')gG;
fileSplitterFetch.splitterStop(); !JrVh$K
qU=$ 0M
F;MFw2G
} M+nz~,![
} >TtkG|/U-T
//负责部分文件的抓取 wt)tLMEv
**FileSplitterFetch.java m\jp$
*/ nq_sbli
package NetFox; \UK 9
L TO1LAac
Lww0LH >
import java.io.*; 6'*?zZrz
import java.net.*; k6*2= xK~
Ng;E]2"
tK]r>?Y\
public class FileSplitterFetch extends Thread { WH'[~O
A\z[/3& RK
T.&^1qWWA
String sURL; //File URL vH7"tz&RIp
long nStartPos; //File Snippet Start Position #M8"b]oh6
long nEndPos; //File Snippet End Position JO1c9NyKr
int nThreadID; //Thread's ID xT=|Uc0
boolean bDownOver = false; //Downing is over w3yI;P
boolean bStop = false; //Stop identical [g<6i.<I
FileAccessI fileAccessI = null; //File Access interface 0~^opNR
8HTV"60hTs
oYqlN6n,=6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^#"!uCq]gM
{ oOJN?97!k
this.sURL = sURL; yNI}=Z
this.nStartPos = nStart; rY($+O@a<
this.nEndPos = nEnd; x~Pv
nThreadID = id; ^WM)UZEBC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h4.ZR={E
} ?M\3n5;
}{9E~"_[
LI(Wu6*Y
public void run() Y+WOU._46I
{ -bKli<C
while(nStartPos < nEndPos && !bStop) 59ro-nA9v
{ L6U[H#3(
xt40hZ$
Oja)J-QXb
try{ mDj:w#q
URL url = new URL(sURL); dr:)+R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V&NOp
httpConnection.setRequestProperty("User-Agent","NetFox"); ^$yr-p%-
String sProperty = "bytes="+nStartPos+"-"; G?8,&jP~T
httpConnection.setRequestProperty("RANGE",sProperty); CXJ0N
Utility.log(sProperty); })ss.
6C) G
+h[$\_y
InputStream input = httpConnection.getInputStream(); 5H?`a7q N
//logResponseHead(httpConnection); @\[&_DZ
gxL5%:@
HiVF<tN
byte[] b = new byte[1024]; K3 "co1]u
int nRead; n_?<q{GW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Po=)jkW
{ #CVD:p
nStartPos += fileAccessI.write(b,0,nRead); uKtrG,/ p
//if(nThreadID == 1) 875V{fvPBU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZYkeW
} f@>27&'WV
8[}MXMRdb
;xwa,1]
Utility.log("Thread " + nThreadID + " is over!"); D<Ads
bDownOver = true; ^9"|tWf6O
//nPos = fileAccessI.write (b,0,nRead); o-7>^wV%BD
} Z.VVY\
catch(Exception e){e.printStackTrace ();} J;'?(xO3\
} sx(yG9
} %VSST?aUvX
G4AX8@;U
O/l|\n
//打印回应的头信息 3P'.)=}
public void logResponseHead(HttpURLConnection con) jskATA /
{ J%D'Xlb
for(int i=1;;i++) d) G7U$z~
{ Px'%5TKN
String header=con.getHeaderFieldKey(i); E%jOJA
if(header!=null) tse(iX/D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aI+:rk^
Utility.log(header+" : "+con.getHeaderField(header)); 8pt;''
else Y@RPQPmIQ
break; +Bc/@.Q'
} =s1"<hH}O)
} hRGK W
c9iCH~
#).om*Xh
public void splitterStop() /3rt]h"
{ 3}n=od=
bStop = true; Lj({ T'f(
} H6rWb6i
a*74FVZo.;
`h :&H,N
} PS(9?rX#+
:uhvDYp(-
In=3#u ,M
/* ZXHG2@E)
**FileAccess.java j:$2,?|5
*//文件访问(定位，写) fd*=`+P
package NetFox; -Qqb/y
import java.io.*; op&,&
Y( D d7`c
t`H^! b
public class FileAccessI implements Serializable{ '_@=9 \<
5K{(V^88F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (/Z~0hA[Q
RandomAccessFile oSavedFile; @T]gwJ
long nPos; T(7 8{A>
>x&$lT{OY
/]<0`nI.
public FileAccessI() throws IOException VLu_SXlo*
{ 9v<BO$ ,a
this("",0); BeaX 0#\
} ~>xn9vb=
7Dom[f
C6CX{IA]
public FileAccessI(String sName,long nPos) throws IOException @QVAsNW:O
{ IS]03_uQ
oSavedFile = new RandomAccessFile(sName,"rw"); >Mrz$ z{x
this.nPos = nPos; $*8c0.{U
oSavedFile.seek(nPos); ;^O^&<
} 09%q/-$
dg/7?gV
(!DH'2I[
public synchronized int write(byte[] b,int nStart,int nLen) -:cS}I
{ fC]+C(*d
int n = -1; @MAk/mb&
try{ (Qq! u
oSavedFile.write(b,nStart,nLen); oQWS$\Rr.
n = nLen; `k_5Pz\
} DV*8Mkzg
catch(IOException e) ?2_u/x
{ 7:{4'Wr@6|
e.printStackTrace (); :14O=C
} p5c'gziR
m!N_TOl-^
H,KU!1p
return n; 9"_qa q
} OQW#BBet@
1\kOjF)l
J A4'e@
} dq"b_pr;
X f!Bsp#\g
RZm5[n
/* 0MrtJNF]_O
**SiteInfoBean.java dSk\J[D
*/ r"Pj,}$A
package NetFox; %49@
_6^vxlF
qJ#?=ITE
public class SiteInfoBean { c<DsCzX
+lO Y IQ
\qV5mD]"M
private String sSiteURL; //Site's URL >xJt&jW-
private String sFilePath; //Saved File's Path {B?%r[nW
private String sFileName; //Saved File's Name H:d{Sru
private int nSplitter; //Count of Splited Downloading File ` n@[=l~
' OdZ[AN
mL18FR N
public SiteInfoBean() 7<|1 xOT
{//nSplitter的缺省值为5 A$Es(<'9g
//default value of nSplitter is 5 V4/P
this("","","",5); v?fB:[dG
} =lr*zeHLC
hLYSYMUb
Uu>YE0/)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) f==o
{ [$8*(d"F'
sSiteURL= sURL; Q:>;d-D|1
sFilePath = sPath; XuoI19V[
sFileName = sName; `lN1u'(:
this.nSplitter = nSpiltter; 8Tt2T} Y
dZ`nv[]k~
u2JkPh&!rq
} pb_mW;JVu
q|=tt(}G
%zb7M%dC6`
public String getSSiteURL() &=X1kQG
{ QbxjfW"/+
return sSiteURL; (@uQ>dR:
} g0cCw2S
UyD=x(li
H,:Cg:E/^
public void setSSiteURL(String value) b;9v.MZ4>g
{ *G'zES0x
sSiteURL = value; @T?:[nPf&F
} R4E0avt
.<rL2`C[c
kOFEH!9&
public String getSFilePath() _+z@Qn?#6h
{ $J=9$.4"
return sFilePath; }Jh!B|
} <*2.B~
ehOF@IA_
D3;^!ln]D
public void setSFilePath(String value) Ibd7[A\
{ W{1=O)w
sFilePath = value; Fl(+c0|kT
} wb"Jj
&AUL]:<s
s:jr/ j!
public String getSFileName() !i.`m-J*
{ 7bQ#M )}
return sFileName; #9#N+
} j 7a;g7.
N#Qby4w >
, $78\B^
public void setSFileName(String value) ^^3 >R`
{ i.0}qS?
sFileName = value; i*9eU*i|H
} o Ep\po1
=QRLKo#_
H]}Iw5Z
public int getNSplitter() 8 6?D
{ ) ;-AT^
return nSplitter; xyBe*,u
} qNC.|R
csH1X/3ha\
F3,hx
public void setNSplitter(int nCount) Ndx.SOj
{ M\e%GJ0
nSplitter = nCount; .F'Fk=N
} O`OntYwa>
} u2-%~Rlo
WTY{sq\' o
1,,o_e\nn3
/* o+/x8:
**Utility.java TcO@q ]+S
*/ k{y@&QNj
package NetFox; .;/@k%>
Pt";f
n#,AZ&
public class Utility { Zhz.8W
7!<cU
Z-Bw?_e_K
public Utility() [AE]0cO@
{ r}D`15IHJ
1i2jYDB"
jW?.>(
} t#6gjfIi
N''9Bt+:
//线程睡眠 G)5%f\&
public static void sleep(int nSecond) k+JDbJ@
{ Gob1V
try{ amlE5GK;
Thread.sleep(nSecond); WASs'Gx
} +)L 'qbCSM
catch(Exception e) S[X bb=n
{ S-.!BQ@RMZ
e.printStackTrace (); FyZw='D
} s-o0N{b?#'
} }"Hf/{E$_"
pYceMZ$
//日志 bYgrKz@uK
public static void log(String sMsg) 'JKFEUzM
{ #*}4=
System.err.println(sMsg); l4L&hY^
} w<-CKM3qe
BU<A+Pe>
wKXKc\r
public static void log(int sMsg) KosAc'/ M
{ vT\`0di~
System.err.println(sMsg); ;w}ZI<ou
} K}&|lCsb
} \AoM'+
iNd8M V
}yx'U 3
/* ]{.rx),
**TestMethod.java TP'EdzAT
*/ cDm_QYQ
package NetFox; hgfCM
_Bb/~^
Y.[^3
public class TestMethod { $-jj%x\}
<M7@JgC &
EAj2uV
public TestMethod() ^qS[2Dy
{ ///xx/weblogic60b2_win.exe T$0//7$')
try{ ,]y)Dy
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0rsdDME[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); FL/@e$AK
SiteFileFetch fileFetch = new SiteFileFetch(bean); "9&6bBa
fileFetch.start(); zRL[.O9
} ! Hdg $,
catch(Exception e){e.printStackTrace ();} H2E!A2\m
K$R1x1lc2
#wk'&XsC#z
} Z+(V'e;
"_}Hzpy5k
tm#T8iF
public static void main(String[] args) TL1pv l
{ lRZt))3
new TestMethod(); 4g$mz:vo
} 4WzB=C(f
} )+u|qT3%
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