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)); nA1059B
} HEBKRpt
for(int i=0;i<nEndPos.length-1;i++) 4;;K1< 1
{ glL.CkJ
nEndPos = nStartPos[i+1]; JnodDH ?
} ^E]Xq]vd"
nEndPos[nEndPos.length-1] = nFileLength; _@] uHp|
} ,Y+J.8.H
} D:Rr|m0Tk
<13').F
%Eq4>o?D
//启动子线程 |i~Ab!*8n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; F4X0DRC,G
for(int i=0;i<nStartPos.length;i++) P&kjtl68Y
{ Ew,1*WK!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xPp\OuwK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "o{o9.w
nStartPos,nEndPos,i); (U?*Z/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .ey=gI!x0
fileSplitterFetch.start(); ps@;Z?Q
} \""sf{S9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b~Q8&z2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); LkK# =v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", y/9aI/O'
nEndPos = " + nFileLength); w+_pq6\V
// fileSplitterFetch[nPos.length-1].start(); Ms61FmA4
q-<t'uhs[
0D.qc8/V4.
//等待子线程结束 ibj3i7G?
//int count = 0; S9VD/
//是否结束while循环 &:@)roCR
boolean breakWhile = false; &)Z!A*w]
:*<UCn""
jM07&o]D
while(!bStop) _&U.DMt2 C
{ Bsc&#
write_nPos(); 2leTEs5aK`
Utility.sleep(500); OF_g0Zu
breakWhile = true; _X/`7!f
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for(int i=0;i<nStartPos.length;i++) Lbwc2Q,.-
{ d!z}! :
if(!fileSplitterFetch.bDownOver) ?nc:B]=pTY
{ 'jr[ ?WQ
breakWhile = false; WJA0 `<~
break; -qW[.B
} y(92Th$
} lHI;fR
if(breakWhile) \.l8]LH
break; ze_q+Z
tQYkH$e`/{
u301xc,N<z
//count++; S?BI)shmg
//if(count>4) 0*{2^\
// siteStop(); Op>l~{{{
} Wm#F~<$
b>]MZhLJe
+5xVgIk#
System.err.println("文件下载结束！"); l'm\*=3
} E,wOWs*
catch(Exception e){e.printStackTrace ();} q1_iV.G<
} QRFBMq}'
)/mBq#ZS
P7D__hoE
//获得文件长度 M9ACaf@
public long getFileSize() Gw@]w;ed
{ U_.9H _G
int nFileLength = -1; j.O+e|kxU
try{ <Y"h2#M"
URL url = new URL(siteInfoBean.getSSiteURL()); 3-6Lbe9H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NO'37d
httpConnection.setRequestProperty("User-Agent","NetFox"); !L?diR
efUa[XO
L<H zPg
int responseCode=httpConnection.getResponseCode(); l)K8.(2
if(responseCode>=400) -)E nr6
{ al@Hr*'
processErrorCode(responseCode); b-Xc6f
return -2; //-2 represent access is error 8H@]v@Z2
} mi'3ibCG
#C#*yE
0hv}*NYd
String sHeader; >HL$=J_K?
^jB17z[
({!S!k
for(int i=1;;i++) sp8P[W1a
{ Wz&[cj
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,9YgznQ
//Utility.log(in.readLine()); e754g(|>b
sHeader=httpConnection.getHeaderFieldKey(i); MiN|u
if(sHeader!=null) k\<8h%
{ @|6#]&v`
if(sHeader.equals("Content-Length")) /L^pU-}Z0
{ }-N4D"d4o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '4e, e|r
break; H63?Erh>a
} aNDpCpy
} ./i5VBP5
else 35 d:r:
break; WWgJ !Uz
} 7w5C NV
} U%V4@iz~\m
catch(IOException e){e.printStackTrace ();} &1Cif$Y4w
catch(Exception e){e.printStackTrace ();} b-?d(-
. ytxe!O
0@>
Utility.log(nFileLength); x%`tWE|
rk8Cea
awU&{<,=g
return nFileLength; 5a%i%+;N
} 'BX U'
1TlMB
p>h}k_s
//保存下载信息（文件指针位置） `dJ?j[P,p
private void write_nPos() 5b$QXO
{ IylfMwLC
try{ zT+ "Z(oz,
output = new DataOutputStream(new FileOutputStream(tmpFile)); o-+H-
output.writeInt(nStartPos.length); MmH(dp+
for(int i=0;i<nStartPos.length;i++) ZLlAK?N
{ OMm'm\+/
// output.writeLong(nPos); (Qd@Q,@(s
output.writeLong(fileSplitterFetch.nStartPos); auHP^O>4L
output.writeLong(fileSplitterFetch.nEndPos); [13NhF3.P
} D!rD-e
output.close(); r1a/'+
} PwC^ ]e
catch(IOException e){e.printStackTrace ();} $E-c%-
catch(Exception e){e.printStackTrace ();} 2Q)pT$
} TXbnK"XQ
WQBpU?O
U.c~l,5%"
//读取保存的下载信息（文件指针位置） gr\vC
private void read_nPos() $D;-;5[-/r
{ 8I<LZ{a10
try{ L8?;A9pc()
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); * TByAa{
int nCount = input.readInt(); j"9Zaq_
nStartPos = new long[nCount]; qF4=MQm\aE
nEndPos = new long[nCount]; Bxk2P<d
for(int i=0;i<nStartPos.length;i++) ,:pKNWY)Q
{ N{?Qkkgx
nStartPos = input.readLong(); +^3 *Y"6Z
nEndPos = input.readLong(); O#`y;%
} "#]V^Rzxh
input.close(); N >k,"=N/
} &Vbcwv@
catch(IOException e){e.printStackTrace ();} mhMRY9ahB
catch(Exception e){e.printStackTrace ();} D)bR-a_^
} Am=O-; b'8
w"AO~LF
B+lnxr0t
private void processErrorCode(int nErrorCode) lFD/hz7lc
{ #Kt5+"+7
System.err.println("Error Code : " + nErrorCode); 5Eu`1f?
} <^"0A
bix}#M
YQaL)t$0
//停止文件下载 c:,K{ZR
public void siteStop() cWp5pGIzfp
{ _SqUPTb"u
bStop = true; m-'+)lB
for(int i=0;i<nStartPos.length;i++) 6B@{X^6y
fileSplitterFetch.splitterStop(); m-R`(
;c|G
'/@i} digf
} \"l/D?+Q
} ^A$p)`KR
//负责部分文件的抓取 v,Yz\onB^
**FileSplitterFetch.java 0ae}!LO
*/ ::!{f+Up
package NetFox; U_AmRiy
%-3wR@
89[OaT_hs
import java.io.*; $<d3g:
import java.net.*; rNeSg=j
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b0[H{q-z{X
public class FileSplitterFetch extends Thread { ?o_D#gG*
?#VkzT
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String sURL; //File URL ="s>lI-1a
long nStartPos; //File Snippet Start Position |"k+j_/+
long nEndPos; //File Snippet End Position TbR!u:J
int nThreadID; //Thread's ID EALgBv>#ZL
boolean bDownOver = false; //Downing is over R2dCp|6A
boolean bStop = false; //Stop identical kqp*o+Oz',
FileAccessI fileAccessI = null; //File Access interface YE1X*'4
2qDVAq^@
NZt 8L?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]VHO'z\m
{ #B8V2_M
this.sURL = sURL; 8?&!@3n
this.nStartPos = nStart; XV:icY
this.nEndPos = nEnd; PVX23y;
nThreadID = id; (-esUOB.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'Y:ZWac,
} j$}W%ibj
p|VgtQ/)%
1|3{.Ed
public void run() m>LC2S; f
{ VT5o#NR{R
while(nStartPos < nEndPos && !bStop) rT28q.
{ !&@!:=X,
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h . R bdG
try{ 1bpjj'2%x
URL url = new URL(sURL); `T~~yM)q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A<P rsk!
httpConnection.setRequestProperty("User-Agent","NetFox"); -`} d@x
String sProperty = "bytes="+nStartPos+"-"; -+Ab[
httpConnection.setRequestProperty("RANGE",sProperty); 0Nq6>^ %
Utility.log(sProperty); ~6O<5@k
8ZvozQE
H\@@iK=
InputStream input = httpConnection.getInputStream(); zIh`Vw,t0
//logResponseHead(httpConnection); GsvB5i
6xAR:
;-@v1I;
byte[] b = new byte[1024]; */E5<DO
int nRead; 7S)u7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <-K'9ut,
{ ieG%D HN
nStartPos += fileAccessI.write(b,0,nRead); >(39K
//if(nThreadID == 1) T{Y;-m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pG(%yIiAi
} Q R<q[@)F
9#ZR0t.cY
z2Rg`1B
Utility.log("Thread " + nThreadID + " is over!"); sQ>L3F;A`
bDownOver = true; Zh,{e/j
//nPos = fileAccessI.write (b,0,nRead); <zhN7="
} ew{(@p+$
catch(Exception e){e.printStackTrace ();} E4dN,^_ F!
} O6Jn$'os1#
} =&xNdc
'Z=8no`<
J'no{3Ktz
//打印回应的头信息 tp3]?@0
public void logResponseHead(HttpURLConnection con) %^ z##7^
{ 'k?*?XxG
for(int i=1;;i++) Uel^rfE`
{ =w <;tb
String header=con.getHeaderFieldKey(i); -kI;yL
if(header!=null) A9L {c!|-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); eJ O+MurO
Utility.log(header+" : "+con.getHeaderField(header)); \>@QJ
else S eTn]
break; % A8dO+W
} 7C"&f *lEi
} p&|:,|jo5
^B`*4
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public void splitterStop() 8%W(",nd
{ N|53|H
bStop = true; xpjv@P
} heN?lmC
6o4Bf|E]
(h3f$
} fce~a\y0
m^M sp:T,
LWp#i8,
/* 'ZboLoS*-
**FileAccess.java Td"_To@jd
*//文件访问(定位，写) qZz?i
package NetFox; aH!2zC\:T
import java.io.*; 1FfSqd
\sZT[42
3+>;$
public class FileAccessI implements Serializable{ Q"+)xj
v62M8r,Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gcKXda(
RandomAccessFile oSavedFile; XD=p:Ezh
long nPos; VQ,;~^Td
aUTXg60l*
+i0j3.
public FileAccessI() throws IOException B !}/4"
{ ;Or]x?-
this("",0); 4ZAnq{nR4
} PZjK6]N\
b|KlWt'
3{*nG'@Mal
public FileAccessI(String sName,long nPos) throws IOException 8,DY0PGP
{ jf WZLb)
oSavedFile = new RandomAccessFile(sName,"rw"); <<5x"W(,
this.nPos = nPos; (+w>hCI
oSavedFile.seek(nPos); W#@Mx
} J+o6*t2|
+IkL=/';#
}S,KUH.
public synchronized int write(byte[] b,int nStart,int nLen) {^jk_G\ys
{ zZ*\v
int n = -1; CL)*cu6zG
try{ 31> $;"
oSavedFile.write(b,nStart,nLen); ![l`@NH[U
n = nLen; 4?2$~\ x
} 8EBy5X}US
catch(IOException e) cq#=Vb
{ W~i599!v
e.printStackTrace (); w$1B|7tX;2
} snm1EPj
];63QJU
Mr6q7
return n; 8`GN8F
} YM<F7tp4
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4Y `=`{Q
} W#sCvI@
=`W#R
vZJu=t
/* WTX!)H6Zv
**SiteInfoBean.java $z[r(a^a
*/ k,0lA#>
package NetFox; *\"+/
4ynGXJmMlR
tYST&5Kh~
public class SiteInfoBean { CjT]!D)s
{wwkbc*
>Nr~7s
private String sSiteURL; //Site's URL "IuPg=|#
private String sFilePath; //Saved File's Path m(rd\3d
private String sFileName; //Saved File's Name x4^*YZc$,
private int nSplitter; //Count of Splited Downloading File D wtvtglqV
5q95.rw
*h)|Ks
public SiteInfoBean() 5ji#rIAhxh
{//nSplitter的缺省值为5 sB+ B,DF
//default value of nSplitter is 5 -(1GmU5v(
this("","","",5); \VAm4
} w3E#v&"=Y
V \Sl->:
wG}Rh,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Zy&?.d[z
{ /pYp,ak
sSiteURL= sURL; dSPye z
sFilePath = sPath; +5xk6RP
sFileName = sName; r$<4_*
this.nSplitter = nSpiltter; eccJt
j&w4yY
56 [+;*
} `Ti?hQm/
SEXmVFsQ
fA" VLQE
public String getSSiteURL() JSu+/rI1
{ kS1?%E,)q
return sSiteURL; C<yjGtVD
} +LB2V3UZ
WNcJ710k27
e763yd
public void setSSiteURL(String value) 2e|m3
{ gvCQ![
sSiteURL = value; 716r/@y$6
} aM!%EaT
\SyG#.$
. l-eJ
public String getSFilePath() R}T\<6Y
{ tr@)zM GB
return sFilePath; s~g0VNu Y
} {jOV8SVL
B*&HQW *u
}2.0e5[
public void setSFilePath(String value) "pTU&He
{ qj1Fj
sFilePath = value; ?AYb@&%
} Kw87 0n<
M&J$9X
HJ0Rcw%
public String getSFileName() <gu>06
{ YlJ_$Q[
return sFileName; XkEE55#>|
} q:<vl^<j
xV>sc;PEb
nl+8C}=u
public void setSFileName(String value) G6q*U,
{ vu|-}v?:
sFileName = value; l dw!G/
} |H&&80I
>B$J
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public int getNSplitter() 4`]
{ 6oy[0hj
return nSplitter; Hd89./v`:
} {4YD_$4W
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}dpE>
public void setNSplitter(int nCount) DSL3+%KF#
{ 8Az|SJ<
nSplitter = nCount; 6ac_AsFK
} Ws;X;7tS
} ]/{iIS_
~*hCTqHvN
N4$ K{
/* L|Bjw3K&D
**Utility.java L!0}&i;u~5
*/ Tl L\&n.$
package NetFox; c!]Q0ib6
:Ny^-4-N
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public class Utility { Svt%*j
`*y%[J,I#
rAh|r}R
public Utility() 52.%f+Oa
{ V>& 1;n
4P}d/w?'KL
=+w/t9I[
} hp$1c
TFDzTD
//线程睡眠 ?\_vqW
public static void sleep(int nSecond) }gKY_e3
{ <z8z\4Hz
try{ K&BaGrR
Thread.sleep(nSecond); )0zg1z
} vQ8$C 3
catch(Exception e) =55V<VI
{ qJ[wVNHh!
e.printStackTrace (); ~toR)=Yv
} KN'twPFq
} z[l_<`J$9
? kCo/sW
//日志 \?[m%$A
public static void log(String sMsg) Q}|0
{ TGuCIc0B{
System.err.println(sMsg); 85BB{T;
} DaqlL
R~BFZF>:
R0e!b+MZ.
public static void log(int sMsg) lcXo>
{ j-zWckT{
System.err.println(sMsg); 8i Ew;I_
} r=#v@]zB
} vHN/~k#
3`Dyrj#!
`KUL4) g~
/* JPpNCC.b
**TestMethod.java zS'{F>w
*/ Tsocc5gWZ*
package NetFox; WS"v"J%
ihD|e&
p+V::O&&r
public class TestMethod { Sg1,9[pb
rBZ00}
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public TestMethod() V o%GO9b;
{ ///xx/weblogic60b2_win.exe x$KQ*P~q
try{ ([]\7}+8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pp()Hu3J
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); rd^j<
SiteFileFetch fileFetch = new SiteFileFetch(bean); uzL|yxt
fileFetch.start(); ~R7{gCqdr
} - XB[2h
catch(Exception e){e.printStackTrace ();} hA+;eXy/
.jl^"{@6
+'aG{/J
} Pt7C/ qM/
).jna`A,
5"w%
public static void main(String[] args) iOiXo6YE
{ ,.V=y%
new TestMethod(); :fQN_*B4@4
} }3R:7N`,|
} 'Me(qpsq
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