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)); s1bU
} hO3{
for(int i=0;i<nEndPos.length-1;i++) /OG zt
{ R&*@@F-dx
nEndPos = nStartPos[i+1]; {n&Uf{
} dxCPV6 XI
nEndPos[nEndPos.length-1] = nFileLength; H O*YBL
} DkdL#sV
} 'mE^5K
35_)3R)
s6n`?,vw
//启动子线程 APq7 f8t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @^&7$#jq%
for(int i=0;i<nStartPos.length;i++) mlB~V3M'G
{ nxfoWy
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~8{sA5y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KP{3iUqvO
nStartPos,nEndPos,i); y3JMbl[S0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s$ z2 c
fileSplitterFetch.start(); T<yb#ak
} KmmQ,e%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2khh4?|\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~KPv7WfG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4-^[%&>}
nEndPos = " + nFileLength); 0[Eb .2I
// fileSplitterFetch[nPos.length-1].start(); )+EN$*H
|>+uw|LtZ
|##GIIv;i
//等待子线程结束 t,HFz6
//int count = 0; .Y\EE;8%
//是否结束while循环 Ee)xnY%(
boolean breakWhile = false; ^2C>L}
jn=:G+0
Ilq=wPD}j
while(!bStop) =wrP:wYF
{ RB$ z]/=
write_nPos(); :c=.D;,
Utility.sleep(500); cbYK5fj"T
breakWhile = true; (s&&>M]r_
Wekqn!h
#^0(
for(int i=0;i<nStartPos.length;i++) i=#F)AD^5#
{ !OAvD#
if(!fileSplitterFetch.bDownOver) %u!b& 5]e
{ +TSSi em
breakWhile = false; v* ~3Z1
break; suVmg-d
} HID([Wk
} NBOCt)C;H
if(breakWhile) r4Q|5kT*i
break; kO_5|6
;gB`YNL
tJU-<{8
//count++; q-_' W,
//if(count>4) Z a(|(M H
// siteStop(); 3CZS)
} 6gU{(H
uM S*(L_
sn{tra
System.err.println("文件下载结束！"); Mu&x_&|
} fk{0d
catch(Exception e){e.printStackTrace ();} m4m<nnM
} |5MbAqjzC
`^6 ,kI-c
~ap2m
//获得文件长度 75NRCXh.
public long getFileSize() AK@L32-S
{ ."6[:MF
int nFileLength = -1; <]d LX}C)
try{ E=w3=\JP
URL url = new URL(siteInfoBean.getSSiteURL()); nc?B6IV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z]@6fM[
httpConnection.setRequestProperty("User-Agent","NetFox"); c$h9/H=~
h"W8N+e\
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int responseCode=httpConnection.getResponseCode(); -t-tn22
if(responseCode>=400) [*4fwk^
{ =.Tv)/ea
processErrorCode(responseCode); fZ{[]dn[
return -2; //-2 represent access is error |FNCXlgZ
} `JURQ:l)3^
N#k61x
r{K;|'d%h
String sHeader; (f#b7O-Wn
=RsXI&&vh
L%h/OD
for(int i=1;;i++) >I'%!E;
{ eV};9VJ$F
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .*5Z"Q['G
//Utility.log(in.readLine()); >)**khuP7
sHeader=httpConnection.getHeaderFieldKey(i); ELD!{bMT
if(sHeader!=null) w0J|u'H
{ \".^K5Pm
if(sHeader.equals("Content-Length")) E>uVofhml
{ ,r^"#C0J}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 57I}RMT"
break; 8P: spD0
} #&8rcu;/
} 7Y( 5]A9=
else Ng=ONh
break; \RG!@$i
} i$^ZTb^
} k%81f'H
catch(IOException e){e.printStackTrace ();} '7)"
catch(Exception e){e.printStackTrace ();} mUP.rb6
)"<8K}%!
:d,^I@]
Utility.log(nFileLength); ajH"Jy3A
N#z~
} cNW^4F
return nFileLength; ~Y!kB:D5;~
} +OHGn;C
U1R4x!ym4
E6MA?Ax&=
//保存下载信息（文件指针位置） 5.0e~zlM-
private void write_nPos() SNpi=K!yn
{ +j/~Af p5f
try{ $)Bg JDr
output = new DataOutputStream(new FileOutputStream(tmpFile)); H=^K@Ti:
output.writeInt(nStartPos.length); <V&5P3)d9
for(int i=0;i<nStartPos.length;i++) 'MxSd(T =
{ pPro }@@
// output.writeLong(nPos); 5/0j}_pP
output.writeLong(fileSplitterFetch.nStartPos); 1DJekiWf
output.writeLong(fileSplitterFetch.nEndPos); NL"G2[e
} )A8v];.]3
output.close(); $jzFc!rs
} hZ$t$3
catch(IOException e){e.printStackTrace ();} dp5cDF}l
catch(Exception e){e.printStackTrace ();} 0 p uY"[c
} HIvZQQW|
j}JZ
F7}-!
//读取保存的下载信息（文件指针位置） _e<o7Y@_
private void read_nPos() T6BFX0$
{ A#y@`}]!'
try{ n6Z|Q@F
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y3U9:VB
int nCount = input.readInt(); +cu^%CXT
nStartPos = new long[nCount]; 2DDsWJ;
nEndPos = new long[nCount]; 7(a2L&k^
for(int i=0;i<nStartPos.length;i++) j;~%lg=)
{ A*yi"{FLi
nStartPos = input.readLong(); ;{Ux_JEg
nEndPos = input.readLong(); Kq6jw/T
} mI1H!
input.close(); p*3; hGp6
} Sv[5NZn0&
catch(IOException e){e.printStackTrace ();} &(pjqV
catch(Exception e){e.printStackTrace ();} Lxl_"kG
} I:j3sy
~mz%E
@mQ:7-,~
private void processErrorCode(int nErrorCode) P ,mN >
{ Gu0 ,)jy\
System.err.println("Error Code : " + nErrorCode); # TkR
} 3R$Z[D-
'Prxocxq
Ri*3ySyb
//停止文件下载 2[yBD-":
public void siteStop() N:5[,O<m_
{ |UUdz_i!:
bStop = true; P5<vf
for(int i=0;i<nStartPos.length;i++) aoW6U{\
fileSplitterFetch.splitterStop(); <yUstz,Xu^
Q;/a F`
LV{Q,DrP
} \3YO<E!t
} (g!p>m!Z
//负责部分文件的抓取 UK[v6".^h
**FileSplitterFetch.java GIwh@4;
*/ ?\=/$Gt
package NetFox; `CE^2
J>vMo@
<'U]`Lp
import java.io.*; Qx3eLfm
import java.net.*; \%jVg\4'
,\)a_@@k
+>f<EPGn
public class FileSplitterFetch extends Thread { Q9F)
W&Y"K)`
VyLH"cCv
String sURL; //File URL eDKxn8+(H
long nStartPos; //File Snippet Start Position [#^#+ |{\
long nEndPos; //File Snippet End Position E>jh"|f:{
int nThreadID; //Thread's ID a}yXC<}$
boolean bDownOver = false; //Downing is over g=@_Z"
boolean bStop = false; //Stop identical >pL2*O^{9
FileAccessI fileAccessI = null; //File Access interface q>!L6h5]t
i^`9syD
V>-b`e
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~l[ra
{ uq3{hB#
this.sURL = sURL; F"+o@9]
this.nStartPos = nStart; m` AK~O2
this.nEndPos = nEnd; D=f7NVc>Q
nThreadID = id; {}~:&.D
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YvL?j
} Y$>-%KcKeI
bzpFbfb
m!n/U-^
public void run() W~n.Xeu{C
{ )$GIN/i
while(nStartPos < nEndPos && !bStop) 5N$E()m$
{ yBpk$
eU+ {*YJg
4vnUN
try{ f>jwN@(
URL url = new URL(sURL); +|cI:|H>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >TL^>D
httpConnection.setRequestProperty("User-Agent","NetFox"); b&)5:&MI
String sProperty = "bytes="+nStartPos+"-"; d50Vtm\
httpConnection.setRequestProperty("RANGE",sProperty); XKOUQc4!R
Utility.log(sProperty); vT^Sk;E
Sb2v_o
+xv!$gJEj
InputStream input = httpConnection.getInputStream(); z`Wt%tL(
//logResponseHead(httpConnection); :fcM:w&
c,EBF\r8*
\/`?
byte[] b = new byte[1024]; =JLh?Wx
int nRead; x+5k <Xi}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) SUCUP<G
{ 9Ru;`
nStartPos += fileAccessI.write(b,0,nRead); uLeRZSC
//if(nThreadID == 1) 5v.DX`"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <~U4*
} gwkb!#A
|H}sYp
66&EBX}
Utility.log("Thread " + nThreadID + " is over!"); >zvY\{WY
bDownOver = true; +]xFoH
//nPos = fileAccessI.write (b,0,nRead); e'*HS7g
} e9pOisZ;8
catch(Exception e){e.printStackTrace ();} l*aj#%ha
} yGBQ0o7E
} jF ^5}5U
od<b!4k~s
+Lm4kA+aE5
//打印回应的头信息 lU]un&[N
public void logResponseHead(HttpURLConnection con) rsNf$v-*
{ J:dof:q
for(int i=1;;i++) 0X|_^"!
{ GV|9H]_,I
String header=con.getHeaderFieldKey(i); shC;hR&;
if(header!=null) _;9!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Xt/Ksw"wn
Utility.log(header+" : "+con.getHeaderField(header)); 8kL4~(hY
else R,2=&+e
break; D>L2o88
} ] f>]n
} \{\MxXW
hn)a@
.9G<y 4
public void splitterStop() 4R%*Z~
{ .\3`2
bStop = true; 'm=*u SJK
} 8OhDjWVJ
10[Jl5+t
yq[Cq=rBk
} z2c5m
M(q'%XL^
4EP<tV
/* faXx4A2"
**FileAccess.java G\gMC <3
*//文件访问(定位，写) /?-7Fg+,
package NetFox; qOV[TP,
import java.io.*; CG]Sj*SA~
:,pSWfK H
9%)=`W
public class FileAccessI implements Serializable{ |+IZS/W"
J'&#mDU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 E4.SF|=x
RandomAccessFile oSavedFile; Bvjl-$m!v
long nPos; F51.N{'
C_fY %O
V,v[y\
public FileAccessI() throws IOException VObrlOkp
{ S&jesG-F
this("",0); mY!iu(R1
} ?dZt[vAMn
9 t n!t
I3S9Us-\
public FileAccessI(String sName,long nPos) throws IOException ?NNn:tiD
{ ~3h-jK?
oSavedFile = new RandomAccessFile(sName,"rw"); pY8q=Kl
this.nPos = nPos; KGHq rc
oSavedFile.seek(nPos); `em9T oJV
} 0o&MB Dp
=4!nFi
"O>n@Q|
public synchronized int write(byte[] b,int nStart,int nLen) H&}ipaDO
{ Ei>m0 ~<\
int n = -1; qAkx<u
try{ h #Z4pN8T3
oSavedFile.write(b,nStart,nLen); 'rP]Nw
n = nLen; @R~5-m
} 36m5bYMd)
catch(IOException e) { >{B`e`$
{ ) iQ
e.printStackTrace (); _>o-UBb4]T
} w2(guL($
=TvzS%U
0"k|H&
return n; [t]X/O3<
} i=FQGWAUu
`ejUs]SR
y? (2U6c
} Ma-\^S=
$.St ej1
eDO!^.<5
/* u<ySd?
**SiteInfoBean.java AF\T\mtvRm
*/ 7XrfuG*L$
package NetFox; cvsz%:Vs
z+2V4s=
wgeNs9L
public class SiteInfoBean { pj|pcv^
vW,snxK6y&
l?E a#
private String sSiteURL; //Site's URL SJ' % ^
private String sFilePath; //Saved File's Path 7[v%GoE
private String sFileName; //Saved File's Name +m\|e{G
private int nSplitter; //Count of Splited Downloading File #:fQ.WWO
Fnx`Ri
J<j&;:IRd
public SiteInfoBean() dpZ;l 9
{//nSplitter的缺省值为5 Mc sTe|X
//default value of nSplitter is 5 ^S)TO}e
this("","","",5); {43yb_B(
} <S"~vKD'
-#`c5y}P
:Gqy>)CxX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Tn-C>=tR~%
{ DdV'c@rq+
sSiteURL= sURL; V% TH7@y
sFilePath = sPath; F-Z%6O,2
sFileName = sName; ?^HfNp9
this.nSplitter = nSpiltter; OIb
_K2?YY(#>
d4[(8} x$/
} %6j)=IOts
05\dl
9e!NOl\_;.
public String getSSiteURL() f}%D"gz
{ H!e 3~+)
return sSiteURL; RH)EB<PV
} -XoPia2
*2"6fX[
}H:F< z*
public void setSSiteURL(String value) tEd.'D8 s
{ UO`;&e-DB
sSiteURL = value; JD>d\z2QC
} H2gj=krK
gv15t'y9
P'@<:S|
public String getSFilePath() W3W'oo
{ < O*6T%;
return sFilePath; E&$_`m;
} I&c ~8Dw
W~T}@T:EN
CLD-mx|?
public void setSFilePath(String value) ;Z[]{SQ
{ 59uwB('|lH
sFilePath = value; n]W_e
} t5k!W7C
\h<BDk*
UUo;`rkT
public String getSFileName() ]-o"}"3Ef
{ f},oj4P\
return sFileName; ^he=)rBb?
} >M!xiQX
_GQz!YA
jo+w>
public void setSFileName(String value) S&C1TC
{ X8eJ4%
sFileName = value; A?Qa 4i
} 3q[WHwmm
W|k0R4K]]
~%u|[$
public int getNSplitter() @xsP5je]
{ .ujT!{>v/
return nSplitter; yj6@7@l>A
} rI$`9d
`pZs T ^G[
%wV>0gQTf
public void setNSplitter(int nCount) }H4=HDO
{ (oK^c-x
nSplitter = nCount; iyZZ}M
} ylf[/='0K
} Sgb*tE)T
U7mozHS,:9
PHg48Y"Nd
/* (<t_Pru
**Utility.java 9ILIEm:
*/ tHD
package NetFox; `;,Pb&W~
p_*M:P1Ma4
~d{.ng 4K
public class Utility { f"#m=_Xm
? ]sM8Bd}
:R6bq!
public Utility() ^_I} x)i*@
{ M/D)".;
B (/U3}w-
kpwt]]e*
} C`rLj5E%
e)nimq {6
//线程睡眠 G |*(8r()
public static void sleep(int nSecond) +,+vkpL-%
{ a^qNJ?R!
try{ Y-piL8Xc
Thread.sleep(nSecond); Ou>u%
} q+SD6qM
catch(Exception e) 1PaUI#X"2F
{ A\rt6/
e.printStackTrace (); <HWS:'1
} a~h:qpgc
} bo"%0?3n
5\mTr)\R
//日志 1:C:?ZC#c
public static void log(String sMsg) n6WY&1ZE~
{ 3OyS8`
System.err.println(sMsg); LL^q1)o
} pi(-A
D8{D[fJ;
zxb/
public static void log(int sMsg) i[C~5}%
{ 'PZ|:9FX!
System.err.println(sMsg); 9DQ)cy
} >$677
} >t,M
%1 KbS [
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/* djQv[Vc{
**TestMethod.java ]e:/"
*/ K`}{0@ilCw
package NetFox; %Kh4m7
8rZ!ia!
CF!Sa6
public class TestMethod { MmPU7Nl%X
_3iHkQr
#H [Bb2(j
public TestMethod() 72W,FU~OD
{ ///xx/weblogic60b2_win.exe I7+9~5p
try{ `Ycf]2.,$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R9We/FhOY
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QB!~Wh
SiteFileFetch fileFetch = new SiteFileFetch(bean); m8Vdb"0
fileFetch.start(); Y&H}xn
} dhg~$CVO
catch(Exception e){e.printStackTrace ();} #TK~eHi
BC>=B@H0
i=a-<A5x
} 2'jOP"G
#qU-j/Qf
gbOpj3
public static void main(String[] args) !{et8F@d|
{ j*@l"V>~
new TestMethod(); n>3U_yt6b
} V!%jf:k
} IH48|sa
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