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)); wZm=h8d
} )_nc;&%w
for(int i=0;i<nEndPos.length-1;i++) n1xN:A
{ "p~1|?T
nEndPos = nStartPos[i+1]; QviH+9
} s:y=X$&M
nEndPos[nEndPos.length-1] = nFileLength; *a7&v3X
} u@$C i/J*
} u;Q'xuo3
b;O|-2AR
nx >PZb
//启动子线程 %Ln7{w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Y|=/*?o}
for(int i=0;i<nStartPos.length;i++) tF<|Eja*
{ q|. X[~e|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e8@@Pi<sB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h@"dpmpe
nStartPos,nEndPos,i); 6*/o
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H`$s63
fileSplitterFetch.start(); {%5tqF
} C{ {DZ*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L+PrV y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0'm4 )\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ajayj|h
nEndPos = " + nFileLength); ~)#JwY
// fileSplitterFetch[nPos.length-1].start(); gNO<`9q
0FFx
Oi=>Usd
//等待子线程结束 YN ~7nOw
//int count = 0; k4+F
//是否结束while循环 >*v^E9Y
boolean breakWhile = false; s:UQ~p}"S
V Z[[zYe
$*bd})y)I
while(!bStop) 99}n%(V
{ f_r1(o5:Y
write_nPos(); 37wm[Z
Utility.sleep(500); Z;aQ/n[`
breakWhile = true; ;Bo{.916
I%43rdoPe
tdn[]|=
for(int i=0;i<nStartPos.length;i++) ^<R*7mB*
{ !+4}x;!8
if(!fileSplitterFetch.bDownOver) y8Bi5Ae,+1
{ }MDuQP]
breakWhile = false; Kv[,!P"Y
break; qHfs*MBJ%
} *BYSfcX6
} /s>ZT8vaAs
if(breakWhile) sY=fS2b#)
break; ;K[`o/#4"
Q9N=yz
'Lft\.C
//count++; Uc6BI$Fmz
//if(count>4) kn_%'7
// siteStop(); g_}r)CgG|
} '!64_OMj'
!Jw
Af:4 XSO6
System.err.println("文件下载结束！"); y(B~)T~e@
} ,>n 4 `A
catch(Exception e){e.printStackTrace ();} z)'dDM D"
} q#-szZQ
\.A~>=:
R/M:~h~F!
//获得文件长度 ur-&- G^
public long getFileSize() BlS0I%SN
{ @4m_\]Wy
int nFileLength = -1; nJF"[w,?
try{ :2?J#/o
URL url = new URL(siteInfoBean.getSSiteURL()); inavi5.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9)Y]05us
httpConnection.setRequestProperty("User-Agent","NetFox"); Rx*T7*xg{
L=Q-r[
9}Tf9>qP>M
int responseCode=httpConnection.getResponseCode(); '2a}1?
if(responseCode>=400) t$8f:*6(*
{ _cx}e!BK#
processErrorCode(responseCode); '+NmHu:q
return -2; //-2 represent access is error v9Oyboh(y
} 4^VY
;8;nY6Ie
g6$X {
String sHeader; EN()dCQHr
BclZsU=xn
-c!{';Zn
for(int i=1;;i++) 8w~I(2S:#
{ ^:K"Tv.=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !'Xk=+
//Utility.log(in.readLine()); zr?%k]A%UO
sHeader=httpConnection.getHeaderFieldKey(i); %-|Po:6
if(sHeader!=null) 2"C'Au
{ !SIGzj
if(sHeader.equals("Content-Length")) |]~tX zY
{ A"k6n\!n;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Aj.TX%}`h
break; nI%0u<=d
} VcT(n7
} {j[[E/8N!y
else k/O|ia6
break; =Z iyT$p
} ; )O)\__"-
} B=#rp*vwL
catch(IOException e){e.printStackTrace ();} l/`<iG%
catch(Exception e){e.printStackTrace ();} h{S';/=8
`f}c 1
9ulJZ\cQ
Utility.log(nFileLength); 9j:t}HV
<wxI>T}b
e~c;wP~cO
return nFileLength; &h-d\gMJ
} ?7^H1L
ePK^v_vBD
H^p?t=Y
//保存下载信息（文件指针位置） fQlR;4QX]
private void write_nPos() ~d ~$fR
{ e//28=OH
try{ Ttb@98
output = new DataOutputStream(new FileOutputStream(tmpFile)); p8Di9\}
output.writeInt(nStartPos.length); Ec[=~>;n{l
for(int i=0;i<nStartPos.length;i++) ($'rV!}
{ Zgt, 'T
// output.writeLong(nPos); Miqu
output.writeLong(fileSplitterFetch.nStartPos); 0O+s3#"?@
output.writeLong(fileSplitterFetch.nEndPos); b~
} AYd7qx:~
output.close(); 0tm%Kd
} :S0r)CNP
catch(IOException e){e.printStackTrace ();} rAwq$!xx
catch(Exception e){e.printStackTrace ();} Xdsd5 UUM
} |dpOE<f[
VjSb>k
K0yTHX?(.
//读取保存的下载信息（文件指针位置） K7Kd{9-2
private void read_nPos() 41mg:xW(J
{ b[?6/#N
try{ /d9I2~}B
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [#kfl
int nCount = input.readInt(); RtGETiA\b
nStartPos = new long[nCount]; 'N)&;ADx-G
nEndPos = new long[nCount]; L{ ?& .iA
for(int i=0;i<nStartPos.length;i++) z9U<Z^4z+
{ Vc$x?=
nStartPos = input.readLong(); 2I(0EBW
nEndPos = input.readLong(); ,Ww)>O+
} nM34zVy
input.close(); OljUK,I]
} ;FQAL@"Yj
catch(IOException e){e.printStackTrace ();} *qj @y'1\
catch(Exception e){e.printStackTrace ();} 4Z"DF)+}
} *TVr| to
'0GCaL*Sd
pvQw+jX
private void processErrorCode(int nErrorCode) D)8&v`LS
{ a9mLPP
System.err.println("Error Code : " + nErrorCode); I1BVqIt1i
} *L%HH@] %_
F(^vD_G
oqB(l[%z2
//停止文件下载 JGX E{FT
public void siteStop() _W/s=pCh
{ fySzZ
bStop = true; mEv<r6qDT
for(int i=0;i<nStartPos.length;i++) N\l\ M
fileSplitterFetch.splitterStop(); _N$3c<dY'
z 3fS+x:E{
[!,&A{.!
} c<wsWs 4V
} ,>V|%tD'
//负责部分文件的抓取 ++-HdSHY
**FileSplitterFetch.java nZ>qM]">u
*/ 8]]uk=P
package NetFox; ]Vo;ZY_\
4 FW~Y
%N7b XKDP
import java.io.*; 3haYb`
import java.net.*; W~aVwO'(
^](sCE7
Zk__CgS#
public class FileSplitterFetch extends Thread { /T]2ZX>
CO%7^}xSE,
GL_YT.(!
String sURL; //File URL T=(/n=
long nStartPos; //File Snippet Start Position UX;?~X
long nEndPos; //File Snippet End Position VUxuX5B3M
int nThreadID; //Thread's ID Xa=oryDt
boolean bDownOver = false; //Downing is over tq H7M0Ry
boolean bStop = false; //Stop identical V$VqYy9 *
FileAccessI fileAccessI = null; //File Access interface 9cp-Rw<tI
Urj8v2k
I?uU}NK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %%)"W n#`
{ UBzX%:A
this.sURL = sURL; t,#7F$t
this.nStartPos = nStart; u\ro9l
this.nEndPos = nEnd; $~!%Px)
nThreadID = id; C$(US8:{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g(B&A P_e
} KV9'ew+M
,7KP
K#_&}C^-jY
public void run() <{GpAf8-
{ _VGAh:v
while(nStartPos < nEndPos && !bStop) -KhNsUQk
{ kfr' P u
f6vhW66:?x
#<s6L"Z-
try{ 2-728
URL url = new URL(sURL); W@`2+}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {^=T&aCYdS
httpConnection.setRequestProperty("User-Agent","NetFox"); Q^prHn*@
String sProperty = "bytes="+nStartPos+"-"; aUa.!,_dh
httpConnection.setRequestProperty("RANGE",sProperty); a$r- U_?
Utility.log(sProperty); r&oR|-2hRk
.A<G$ db ?
4~xKW2*`K
InputStream input = httpConnection.getInputStream(); k\BJs@-
//logResponseHead(httpConnection); L[lX?g?Ob
z`$jxSLm
yiO!ZT
byte[] b = new byte[1024]; nNz1gV:0X
int nRead; G d~ v _
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %c"PMTq(
{ qmqWMLfC
nStartPos += fileAccessI.write(b,0,nRead); @W6:JO
//if(nThreadID == 1) WfpQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fb-Lp#!T39
} FlGU1%]m
pqe7a3jr
:dq.@:+<R
Utility.log("Thread " + nThreadID + " is over!"); 94VtGg=b}
bDownOver = true; SQ8xfD*
//nPos = fileAccessI.write (b,0,nRead); \ne1Xu:hM
} d-c<dS+R
catch(Exception e){e.printStackTrace ();} s|F}Abx,^
} /Cy4]1dw
} <|Srbs+
7]W6\Z
"@^Pb$BLY
//打印回应的头信息 ze2%#<
public void logResponseHead(HttpURLConnection con) *N>n5B2
{ b.I_
for(int i=1;;i++) Z,zkm{9*
{ }py)EI,U
String header=con.getHeaderFieldKey(i); B-^r0/y;
if(header!=null) kvcDa+#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Em)U`"j/9
Utility.log(header+" : "+con.getHeaderField(header)); S&/,+x'c|
else pHQrjEF*
break; +7\$wc_1I@
} \ vn!SO7
} JguPXHa0
aItQ(+y
#1*#3p9UL
public void splitterStop() [wU e"{
{ R!i\-C1 S
bStop = true; V=^B7a.;>
} U\*]cw
VyX5MVh
C7*n<+e
} :I_p4S.)
Z$?(~ln
{uUV(FzF6
/* r1<dZtb
**FileAccess.java i>z_6Gax*[
*//文件访问(定位，写) m)AF9#aT2
package NetFox; !/nXEjW?
import java.io.*; Q^\m@7O :
SR%k|YT
5aj%<r
public class FileAccessI implements Serializable{ i;Dj16h
Q g~cYwX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |RjAp.pm
RandomAccessFile oSavedFile; nQGl]2
long nPos; Ft E5H
Zd5Jz+f
'tTUro1~
public FileAccessI() throws IOException R2Es~T
{ -pmb-#`M
this("",0); Gj_7wP$
} 9?X8H1
{W+IUvn
)ifjK6*
public FileAccessI(String sName,long nPos) throws IOException :FTx#cZ
{ XHU\;TF
oSavedFile = new RandomAccessFile(sName,"rw"); QC,fyw\
this.nPos = nPos; x~Y{ {
oSavedFile.seek(nPos); H;nEU@>"Z
} 'C4cS[1
LBxmozT
@E 8P>kq
public synchronized int write(byte[] b,int nStart,int nLen) @An}
{ 0=0,ix7?#
int n = -1; \sMe2OL#z
try{ *\.8*6*$!
oSavedFile.write(b,nStart,nLen); rJZR8bo
n = nLen; lArKfs/
} +7\d78U
catch(IOException e) '-U&S
{ ]p8zT|bv
e.printStackTrace (); * N]^(+/A
} SZ29B
l+#J oc<8
0iYo&q'n
return n; _01wRsm%2
} nb<e<>L
80zpRU"
_tUh*"e&
} V&*|%,q
iYZn`OAx
_9g-D9
/* O8OAXRt/Y
**SiteInfoBean.java (xfh 9=.
*/ .TMLg(2hgv
package NetFox; }* \*<d 3
,ZghV1z
MaPOmS8?
public class SiteInfoBean { fat;5XL@
3eg6 CdT
^T:L6:
private String sSiteURL; //Site's URL ph}%Ay$
private String sFilePath; //Saved File's Path 2x>7>;>
private String sFileName; //Saved File's Name a^={X<K|/
private int nSplitter; //Count of Splited Downloading File MyZVx|7E
ZIKSHC9
2X<%BFsE
public SiteInfoBean() %x.du9
{//nSplitter的缺省值为5 ]1FLG*sB
//default value of nSplitter is 5 TjDtNE
this("","","",5); 'hE'h?-7
} qA;Gl"HF
uu9IUqEq2
(\D E1q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) d~AL4~}
{ ta6>St7.
sSiteURL= sURL; l\F71pwSI
sFilePath = sPath; #dKy{Q3he
sFileName = sName; 42~.N=2
this.nSplitter = nSpiltter; )X;051Q
Y)@Y$_
J5(0J7C
} iciKjXJ:
NRny]!
xP_/5N=f
public String getSSiteURL() *Y?oAVkz
{ 4(*PM&'R
return sSiteURL; )Gavjj&uJ
} DuNindo8
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YA@MLZm
public void setSSiteURL(String value) c7~R0nP
{ cnS;9=,&
sSiteURL = value; |.,]0CRg
} pHuR_U5*?
^B0Qk:%P^N
WW.@&#S5
public String getSFilePath() }toe'6
{ m~ 5"q%;
return sFilePath; cF4,dnI
} J$sBfOD
~+j2a3rv-{
P3`$4p?
public void setSFilePath(String value) 0PqI^|!
{ V y$*v
sFilePath = value; 4e/!BGkAS
} }NoP(&ebz*
gyD;kn\CP
i(pHJP:a:
public String getSFileName() 2,dWD<h
{ $'I&u
return sFileName; D HT^.UM28
} /2zan}
Pw| h`[h
nj0sh"~+
public void setSFileName(String value) l 9 wO x
{ $,2T~1tE
sFileName = value; PcEE`.
} Yb-{+H8{J
zPND$3&'
[nZIV
public int getNSplitter() b~}$Ch3ymW
{ |4g0@}nr+W
return nSplitter; /W)A[jR
} =qc+sMo
hrtz>qN
!ig&8:
public void setNSplitter(int nCount) OtoM
{ hiBsksZRnk
nSplitter = nCount; GyWa=KW.u
} 71\53Qr#U
} 3ZI7;Gw
njf\fw_
C<AW)|r_
/* &n )MGg1%
**Utility.java &:g:7l]g
*/ (z>t4(%\
package NetFox; {@vnKyf^K
?9a%g\`?:
F^'$%XKV
public class Utility { YO.+-(
8k95IJR1
fCx(
public Utility() +x=)Kp>
{ <|4$TH^t
>P:X\5Oj
hK{H7Ey*
} 5\MC5us3
#'q7 x
//线程睡眠 Inv`C,$7Q#
public static void sleep(int nSecond) ?' .AeoE-
{ m<hP"j
try{ E{&MmrlL,
Thread.sleep(nSecond); .a]#AFX
} -1,0hmn=+
catch(Exception e) /V:9*C
{ [K.1 X=O}
e.printStackTrace (); Q}|K29Y:p
} 3y6\0|{1
} Q0Ft.b
X)[tb]U/Wx
//日志 }a||@unr
public static void log(String sMsg) -p&u=
{ L)bMO8JH~m
System.err.println(sMsg); A}SGw.3
} 0o=HOCL\
^"X.aksA
U_(>eVi7F
public static void log(int sMsg) qU7_%Z
{ >Ua'*
System.err.println(sMsg); ^sD M>OHp
} -3R:~z^L
} e4YP$}_L
)&c#?wx'w
:rUMmO-
/* IibrZ/n6
**TestMethod.java X`KSj N&(
*/ 3NtUB;!
package NetFox; $+'H000x
I_ mus<sE
@gD)pH
public class TestMethod { D*%am|QL
('5?-
bQt:=>
public TestMethod() R+M=)Z
{ ///xx/weblogic60b2_win.exe g#J aw|N
try{ KdR4<qVV}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); a{]=BY oL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \X8b!41
SiteFileFetch fileFetch = new SiteFileFetch(bean); *y*tI}
fileFetch.start(); "CT}34l
} W%!(kN&d
catch(Exception e){e.printStackTrace ();} 8wsU`40=Q
0>sa{Z
9GD0jJEu
} {cm?Q\DT
_RbfyyaN
=X4Fn^w"4O
public static void main(String[] args) zuvPV{ X
{ ~=|}!A(
new TestMethod(); N)X Tmh2v|
} '47 b"uV
} !g|O.mt
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