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)); +a'QHtg
} D+$k
for(int i=0;i<nEndPos.length-1;i++) TTNgnP
{ -KzU''
nEndPos = nStartPos[i+1]; /cmnX'z
} $^&SEz
nEndPos[nEndPos.length-1] = nFileLength; q\ihye
} !sF! (u7
} <9za!.(zu
OBF3)L]
}h+_kRQ
//启动子线程 TWv${m zE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2m`4B_g A
for(int i=0;i<nStartPos.length;i++) :V)W?~Z7B
{ i&cH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @(:ah
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _ F0qqj
nStartPos,nEndPos,i); Dq T)%a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R'E8>ee;^
fileSplitterFetch.start(); Y~RZf /`
} 7V/yU5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7e,<$PH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #xWC(*Ggp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $Cu/!GA4.>
nEndPos = " + nFileLength); *q5'~)W<
// fileSplitterFetch[nPos.length-1].start(); ]mU,y$IQ
0 O{Y Vk`
!;Mh5*-
//等待子线程结束 ETu7G5?
//int count = 0; o?G^=0T
//是否结束while循环 +B*8$^,V)
boolean breakWhile = false; MSEBvZ-
wu*WA;FnA
Kuh! b`9
while(!bStop) ]Ll<
{ Q]*YIb~D
write_nPos(); C,C=W]G
Utility.sleep(500); DdI7%?hK
breakWhile = true; !'14mN#A
V/5hEoDt
h6*=Fn7C
for(int i=0;i<nStartPos.length;i++) T[$Sbz`
{ `1%SXP1
if(!fileSplitterFetch.bDownOver) v}6YbY Tq
{ #Id.MLHxA_
breakWhile = false; &`7~vA&c
break; ':,6s
} )k&pp^q\
} ujcS>XN,1
if(breakWhile) `92 D]^g
break; ArkFC
c%.f|/.k
9X&Xs/B
//count++; >/"XX,3
//if(count>4) H*QN/{|RU
// siteStop(); ~qNpPIrGr
} =#XsY,r
nf< <]iHf
TJtW?c7
System.err.println("文件下载结束！"); @S~'m;
} }iy`Ko+B"b
catch(Exception e){e.printStackTrace ();} zIbl[[M&
} /,v:!*
:,F^{
Vvx(7p-GQ
//获得文件长度 $"{V],:T |
public long getFileSize() ADX}
{ |Sg *j-.
int nFileLength = -1; TGLkwXOkT
try{ a@@!Eg A
URL url = new URL(siteInfoBean.getSSiteURL()); vg5zsR0u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $52Te3n
httpConnection.setRequestProperty("User-Agent","NetFox"); RCt)qh+
@"9y\1u
T4 SByX9
int responseCode=httpConnection.getResponseCode(); "xdJ9Z-B
if(responseCode>=400) xsRMF&8L
{ 3w )S=4lB
processErrorCode(responseCode); i:#R U^R
return -2; //-2 represent access is error ilK8V4k<T)
} :Puv8[1i
"sFdrXJ
Fc}wuW
String sHeader; I#l9
%9mCgHQ9
Kw'Dzz%kN
for(int i=1;;i++) "!)8bTW
{ ,|I\{J #C
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); We#*.nr{3Z
//Utility.log(in.readLine()); v%3)wD
sHeader=httpConnection.getHeaderFieldKey(i); ;lGa.RD[a
if(sHeader!=null) d$rJW m5H
{ KHr8\qLH
if(sHeader.equals("Content-Length")) {(wV>Oc>Jw
{ $!I$*R&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iy tSC
break; MbnV5b:X
} zi>f436-
} 62EJ# q[
else [ur/`
break; mC~W/KReA
} c%~'[W04\
} {yyg=AMz
catch(IOException e){e.printStackTrace ();} C>68$wd>
catch(Exception e){e.printStackTrace ();} Op3 IL/
|ry;'[*
U7crbj;c)d
Utility.log(nFileLength); any\}
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W&06~dI1!
return nFileLength; 8Z3+S)6
} y8+?:=N.
lRt8{GFy
4)j<(5
//保存下载信息（文件指针位置） ]^ O<WD
private void write_nPos() ZuS+p0H"
{ 2L<TqC{,-
try{ ]VJcV.7`
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4d]
output.writeInt(nStartPos.length); 6%S>~L66
for(int i=0;i<nStartPos.length;i++) LO"HwN43h
{ bf;IJ|v^
// output.writeLong(nPos); A94VSUDA:
output.writeLong(fileSplitterFetch.nStartPos); .h+<m7
output.writeLong(fileSplitterFetch.nEndPos); YSrFHVq
} ObM5vrEk|
output.close(); }Pb!u9_
} cjN4U [
catch(IOException e){e.printStackTrace ();} D'nV &m
catch(Exception e){e.printStackTrace ();} &I(|aZx?J
} )%j)*Ymz;
==FzkRA)
X_!mZ\H7
//读取保存的下载信息（文件指针位置） /@#)j( eY/
private void read_nPos() ]}v`#-Px(
{ rW\~sTH
try{ !Rb7q{@>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); iBUf1v
int nCount = input.readInt(); T[Gz
nStartPos = new long[nCount]; 609=o+
nEndPos = new long[nCount]; }= <!j5:
for(int i=0;i<nStartPos.length;i++) RTl7vzG
{ NZlJ_[\$C
nStartPos = input.readLong(); q',a7Tf:
nEndPos = input.readLong(); 8%xtb6#7M
} [2\`Wh:%P
input.close(); )i!)Tv
} SbI,9<
catch(IOException e){e.printStackTrace ();} S?3{G@!
catch(Exception e){e.printStackTrace ();} k6Tpaf^
} !m(6/*PAl
q6G([h7
2PeI+!7s
private void processErrorCode(int nErrorCode) h,p&/oU4U
{ 2!6Kzq
System.err.println("Error Code : " + nErrorCode); b6/:reH{
} I(7gmCV
shn-Es*
L0_=R;.<
//停止文件下载 dJ&s/Z/>E
public void siteStop() >y8Z{ALQ5
{ 3o^V$N.
bStop = true; 57MoO
for(int i=0;i<nStartPos.length;i++) \U-5&,fP
fileSplitterFetch.splitterStop(); 7I44BC*R~
E Fv+[
eqf~5/Z
} /gdo~
} $OhL 95}7
//负责部分文件的抓取 eD(a +El}
**FileSplitterFetch.java T]zjJwa
*/ g1{wxBFE
package NetFox; 9E#(iP
oaXD^H\
+es6c')
import java.io.*; %4-pw|':
import java.net.*; hBqu,A
U&/S
>S3 >b
public class FileSplitterFetch extends Thread { <A&R%5Vs
*oWzH_
=N0cz%
String sURL; //File URL =~S
long nStartPos; //File Snippet Start Position o{Ep/O`
long nEndPos; //File Snippet End Position uJ y@
int nThreadID; //Thread's ID vVf!XZF
boolean bDownOver = false; //Downing is over )/pPY
boolean bStop = false; //Stop identical 5(|ud)v
FileAccessI fileAccessI = null; //File Access interface HWU{521
ZT8j9zs
Oxvw`a#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A&7jE:Ew
{ `&6]P:_qp
this.sURL = sURL; puyL(ohem
this.nStartPos = nStart; j w462h
this.nEndPos = nEnd; >k#aB.6
nThreadID = id; {2Ibd i
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;5l|-&{@*
} [eN{Ft0x
,5?MRqCM
W!^=)Qs
public void run() w#$k$T)
{ J|q_&MX/
while(nStartPos < nEndPos && !bStop) mNYz7N
{ _L72Ae(_
xd.C&Dx5
?(=B=a[
try{ $g^;*>yr
URL url = new URL(sURL); )5v .9N6v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cA\W|A)
httpConnection.setRequestProperty("User-Agent","NetFox"); K!~](_W!
String sProperty = "bytes="+nStartPos+"-"; <>oW f
httpConnection.setRequestProperty("RANGE",sProperty); iau&k`b`
Utility.log(sProperty); R}Y=!qjYE=
:F\f}G3
E;Hjw0M'k
InputStream input = httpConnection.getInputStream(); {cI<4><
//logResponseHead(httpConnection); J)-> 7h=
A~>=l=
y_&XF>k91
byte[] b = new byte[1024]; X9j+$X\j
int nRead; =R"tnjR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N-|Jj?c
{ bW|y -GM
nStartPos += fileAccessI.write(b,0,nRead); O5?Eb
//if(nThreadID == 1) yB1>83!q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u2Obb`p S
} ?rDwYG(u]@
a40BisrD~6
xL"%2nf
Utility.log("Thread " + nThreadID + " is over!"); F)w83[5_d
bDownOver = true; 8IH gsW";
//nPos = fileAccessI.write (b,0,nRead); I2T2'_I
} k#&SWp=
catch(Exception e){e.printStackTrace ();} .#J3UZ
} co80M;4
} :\OvVS/
~dLZ[6Z
nSiNSLv
//打印回应的头信息 H%N+Vr3O,
public void logResponseHead(HttpURLConnection con) xTZ5q*Hqx
{ uSJP"Lw
for(int i=1;;i++) pAuwSn#i
{ 5XHkRcESZ
String header=con.getHeaderFieldKey(i); {LDb*'5Cy
if(header!=null) k]iS3+nD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~=ktFuEa
Utility.log(header+" : "+con.getHeaderField(header)); bYc qscW
else HWBom8u0
break; 5aNDW'z`f
} lg+g:o
} Sq,ty{j2%
Qg!*=<b
zY+Et.lg]^
public void splitterStop() 3(&F.&C$$
{ EYG E#C; d
bStop = true; #^ #i]{g
} ZtoE=7K
du,-]fF
y9hZ2iT
} w#,v n8
R-fjxM*
f4_G[?9,
/* '=.Uz3D'0
**FileAccess.java JUFO.m^w
*//文件访问(定位，写) Q8oo5vqQ#C
package NetFox; |plo65
import java.io.*; *Mc\7D
:t^})%
C>dJ:.K%H
public class FileAccessI implements Serializable{ iGk{8Da<
{B.]w9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q?4uH;h:^G
RandomAccessFile oSavedFile; A5ID I<a
long nPos; Uc0'XPo3I
MlE~gCD
h';v'"DoW`
public FileAccessI() throws IOException e&4u^'+K
{ CD[=z)<z{
this("",0); G\ZRNb
} :q<%wLs
m4>oE|\
h_yR$H&tX
public FileAccessI(String sName,long nPos) throws IOException &X,)+b=
{ %iC63)(M
oSavedFile = new RandomAccessFile(sName,"rw"); y03a\K5[KQ
this.nPos = nPos; OZm[iH
oSavedFile.seek(nPos); MToQ8qKs
} .G~5F- 8'
'LLx$y.Ei[
#%"TU,[+
public synchronized int write(byte[] b,int nStart,int nLen) UO<claV
{ R7c)C8/~
int n = -1; *AR<DXEL
try{ Ki6.'#%7
oSavedFile.write(b,nStart,nLen); NV4W2thYo
n = nLen; >%dAqYi $
} ibs"Iv34
catch(IOException e) }zxh:"#K
{ O>5u5n
e.printStackTrace (); NOp=/
} 6G$tYfX
xH#a|iT?(
RyWOiQk;
return n; Yj/nzTVJ[
} !DL53DQ#
nY-9 1q?Y
'OW"*b
} p!QneeA`&X
m+{: ^
U2lC !j%K
/* @M^QhHs
**SiteInfoBean.java PVc|y.
*/ YPDsE&,J)
package NetFox; 7d8qs%nA
T)tHN#6I
pbxcsA\
public class SiteInfoBean { Lj-&TO}OZ
aq/Y}s?
@<yc .>
private String sSiteURL; //Site's URL :wmf{c
private String sFilePath; //Saved File's Path 6ilC#yyp
private String sFileName; //Saved File's Name ]J=)pDrk
private int nSplitter; //Count of Splited Downloading File /1#Q=T
xWe1F2nY
vP)~j1
public SiteInfoBean() E(kb!Rz
{//nSplitter的缺省值为5 p<fgUVR
//default value of nSplitter is 5 wK`ieHmp
this("","","",5); xYVjUb(,X
} D4]B>
4U;XqUY /
Q<-%jBP
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 64rk^Um
{ $RNUr \9A
sSiteURL= sURL; a{Hb7&
sFilePath = sPath; IetGg{h.
sFileName = sName; VD&3%G!
this.nSplitter = nSpiltter; ?[1qC=[Z<
15T[J%7f
9AddF*B
} J}_Dpb[L
,3--ERf
,!%R5*?=D
public String getSSiteURL() 8Y~=$5>
{ Cm<j*Cnl
return sSiteURL; S}Y|s]6
} {r2|fgi
zpr@!76
C9Z\G 3
public void setSSiteURL(String value) %x8`fm
{ <eFAI}=s
sSiteURL = value; J[Yg]6
} CC(*zrOd-
S{(p<%)[
q(tGbhQ
public String getSFilePath() P(gVF|J?
{ ?(ls<&s{w
return sFilePath; 8u5 'g1M
} ,\9mAt1O
u}LX,B-n(
m5em<P!G
public void setSFilePath(String value) dGD^op,6g
{ DEQE7.]3q
sFilePath = value; CL'Xip')T
} xgT~b9
hn\Q6f+
K_+;"G
public String getSFileName() oSA*~N:
{ b801OF
return sFileName; LUDJPIk
} |~bR.IA
DMcxa.Sd!
Ag4Ga?&8ec
public void setSFileName(String value) -6~y$c&c
{ 1.95 ^8
sFileName = value; eBC%2TF
} ZecvjbnVY
,WB_C\.#XN
Z-h7
public int getNSplitter() +5t bK
{ 7Cd_zZ
return nSplitter; X:``{!~geo
} u|OzW}xb7j
G>w?9:V}
^2C /!Y<
public void setNSplitter(int nCount) :EmQ_?(^
{ KW|$83$
nSplitter = nCount; 2Jo~m_
} ig2+XR#%
} ImV]}M~_
ey\m)6A$
E R]sDV
/* BF@5&>E
**Utility.java {s8U7rmML
*/ << ;HY}s
package NetFox; (e8G (
]Q4PbW
WfDX"rA
public class Utility { M,t*nG
C3\E.u?
"7yNKO;W
public Utility() &`yOIX-H_
{ Gh2Q$w:
@<OO
5Z9~ &U
} Z<ajET`)
<wt$Gglk
//线程睡眠 'cAc{\)
public static void sleep(int nSecond) .;HIEj zq
{ J}(6>iuQY?
try{ ;;?vgrz
Thread.sleep(nSecond); ```d:f
} 1X::0;3
catch(Exception e) 7k]RO
{ l 70,Jo?78
e.printStackTrace (); jWXR__>.
} %0yS98']g
} k6O.H
I%9bPQ
//日志 3T|Y}
public static void log(String sMsg) Ts(t:^
{ j1puB
System.err.println(sMsg); -Aa]aDAz68
} WDEe$k4.
!.3R~0b
% Cu.u)/+
public static void log(int sMsg) WGh. ;-
{ wy{\/?~c
System.err.println(sMsg); (A29ZH
} -!J2x8Ri
} W}XYmF*_?
`l>93A
gwSN>oj &
/* /Fv/oY
**TestMethod.java 0%s3Mp6H
*/ L`UG=7r q
package NetFox; Q PFeBl
<t{?7_ 8
s) Cpi
public class TestMethod { JBR[; zM
!TP6=ks
ohrw\<xsu
public TestMethod() g4:VR:o
{ ///xx/weblogic60b2_win.exe %5JW<9
try{ 9<|m4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); a`H\-G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); FUaI2
SiteFileFetch fileFetch = new SiteFileFetch(bean); +7Yu^&
fileFetch.start(); hCzjC|EO~
} #(%t*"IY;
catch(Exception e){e.printStackTrace ();} )n7|?@5U
|l|_dn
[J0*+C9P*
} ^ <qrM
CQdBf3q
tTotPPZf}
public static void main(String[] args) YP[LQ>
{ 'nRp}s1^[
new TestMethod(); NJZXs_%>$
} n6b3E*
} 6*ZU}xT
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