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)); >#N[GrJAE
} h[=nx^
for(int i=0;i<nEndPos.length-1;i++) 6f]rQ9
{ yBn_Kd
nEndPos = nStartPos[i+1]; jM__{z
} x0Bw{>Q
nEndPos[nEndPos.length-1] = nFileLength; ,86K
} /)V4k:#b
} fA8ozL T
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T{-2fp8r[
//启动子线程 3eg5oAZ)G8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; W^xZ+]
for(int i=0;i<nStartPos.length;i++) Zg $Tf
{ 3ps,uozj
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C{Blqf3V0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D@vMAW
nStartPos,nEndPos,i); #@_1fE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (K!4Kp^m
fileSplitterFetch.start(); SFO&=P:U
} D<nxr~pQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d=e{]MG(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .C5@QKU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T"W9YpZ
nEndPos = " + nFileLength); %ejeyc
// fileSplitterFetch[nPos.length-1].start(); 3Xdn62[&
R [9w
exphe+b
//等待子线程结束 Kpg:yrc['
//int count = 0; VG#Q;Xd}
//是否结束while循环 V.,bwPb{9
boolean breakWhile = false; K+mU_+KRp
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j-* TXog
while(!bStop) K/Jk[29"\
{ 2X_>vIlEm
write_nPos(); qeMv Vf
Utility.sleep(500); l10-XU02
breakWhile = true; ~V$ f#X
pbdF]>\
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for(int i=0;i<nStartPos.length;i++) 0P9Wy!f7
{ h[H%:743
if(!fileSplitterFetch.bDownOver) @ta?&Qf)
{ 6z]`7`G
breakWhile = false; %O/d4
break; 5&qY3@I7l
} #PH#2/[
} ]BfR.,,
if(breakWhile) T?e9eYwS
break; k5s?lWH
Nu+wL>t
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//count++; YZ*{^'
//if(count>4) qvTJ>FILT
// siteStop(); 9}XT'+`y
} O0zi@2m?B
VIYV92[
wWFW,3b
System.err.println("文件下载结束！"); >p |yf.G
} xSOoIsL[
catch(Exception e){e.printStackTrace ();} 2H>aC wfX
} H%~Q?4
6JWGu/A
U6a zhi&,
//获得文件长度 !5E9sk{)
public long getFileSize() .~22^k
{ 6puVw-X
int nFileLength = -1; +{Gw9h"5g*
try{ N&N 82OG
URL url = new URL(siteInfoBean.getSSiteURL()); =g[H]-Ee
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {]@Qu"M
httpConnection.setRequestProperty("User-Agent","NetFox"); -3`Isv
9;pzzZ
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int responseCode=httpConnection.getResponseCode(); IrUi Eq
if(responseCode>=400) {DS\!0T-X
{ dh?S[|='
processErrorCode(responseCode); XqX I(q^
return -2; //-2 represent access is error s+N^PX3
} }8 \|1@09
uegb;m
:Lc3a$qtx5
String sHeader; L77EbP`P
#Wq#beBb
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for(int i=1;;i++) 3f,u}1npa*
{ {NY]L==H
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N[]U%9[=2F
//Utility.log(in.readLine()); ny~W]1
sHeader=httpConnection.getHeaderFieldKey(i); T7ki/hjRb
if(sHeader!=null) G ;jF9i
{ rBS2>?
if(sHeader.equals("Content-Length")) ]'E}
{ w2@"PGR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o6:45
break; +&?'KZ+Z_v
} *seu&
} @n>{&^-c
else GA7u5D"0
break; ^xmZ|f-
} 2!{N[*)
} rEg+i@~
catch(IOException e){e.printStackTrace ();} .u&|e
catch(Exception e){e.printStackTrace ();} 8 `o{b"l+
C*$|#.l
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Utility.log(nFileLength); q?1yE@th
:"y0oCu7`W
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return nFileLength; m^5s>hUl
} /AoVl'R
wd"TM
bD d_}
//保存下载信息（文件指针位置） Plb}dID"
private void write_nPos() DqRLx85d1
{ N JXa_&_
try{ jjYM3LQcdP
output = new DataOutputStream(new FileOutputStream(tmpFile)); _qEWu Do
output.writeInt(nStartPos.length); 5a8JVDLX^
for(int i=0;i<nStartPos.length;i++) '+tKvTU;
{ HqB|SWyK
// output.writeLong(nPos); VVgsLQd
output.writeLong(fileSplitterFetch.nStartPos); !W0P`i<
output.writeLong(fileSplitterFetch.nEndPos); !+5C{Hs2
} 4Fh&V{`W
output.close(); `3]Rg0g&Xe
} tx gvVQ
catch(IOException e){e.printStackTrace ();} NYGmLbq
catch(Exception e){e.printStackTrace ();} 7:#
} ^zKt{a
a4Ls^
2\DTJ`Y,
//读取保存的下载信息（文件指针位置） (y%%6#bd
private void read_nPos() `:V}1ioX5
{ uAc@ Z-
try{ IPwj_jvw
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ZK%Kgk[\:~
int nCount = input.readInt(); sbs[=LW4
nStartPos = new long[nCount]; o?;F.W_
nEndPos = new long[nCount]; `8mD7xsg$
for(int i=0;i<nStartPos.length;i++) +}kO;\
{ 4 0p3Rv
nStartPos = input.readLong(); r[6#G2
nEndPos = input.readLong(); U.HoFf+HN
} .MzOLv
input.close(); mu 2 A%"7
} \nrgAC-b
catch(IOException e){e.printStackTrace ();} =DGn,i9
catch(Exception e){e.printStackTrace ();} 44Q6vb?
} '" ^ B&W
UwZu:[T6H
:U!'U;uQ
private void processErrorCode(int nErrorCode) ]jZiW1C*a
{ (zjz]@qJ
System.err.println("Error Code : " + nErrorCode); bELIRM9
} 71JM [2
)3BR[*u*
=X)Q7u".7
//停止文件下载 ,Le&I9*%
public void siteStop() Y;'VosTD
{ F_ ,L2J
bStop = true; ;r gH}r
for(int i=0;i<nStartPos.length;i++) t|go5DXz4
fileSplitterFetch.splitterStop(); AD~~e% s=
eo>/
pQk=x T
} MFf05\aDu
} cWgbd^J
//负责部分文件的抓取 unCt4uX^
**FileSplitterFetch.java Vf"O/o}hq,
*/ x{=[w`
package NetFox; ERUs0na]
;% /6Y~/
q"{Up
import java.io.*; !w @1!Xpn1
import java.net.*; =Jsg{vI
<$RS*n
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public class FileSplitterFetch extends Thread { 2N L:\%wz
>{phyByI
6T R8D\
String sURL; //File URL 83{x"G3>
long nStartPos; //File Snippet Start Position 'LJ %.DJ
long nEndPos; //File Snippet End Position qf_hb
int nThreadID; //Thread's ID *37LN
boolean bDownOver = false; //Downing is over "bHtf_
boolean bStop = false; //Stop identical ~AEqfIx*^&
FileAccessI fileAccessI = null; //File Access interface L4\SBO
ipx@pNW;"
} l:mN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }2-[Ki yv
{ z*Myokhf
this.sURL = sURL; 9\AEyaJFZ
this.nStartPos = nStart; 1m&!l6Jk
this.nEndPos = nEnd; fo/ D3
nThreadID = id; yq/[/*7^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 NmH}"ndv+
} 2E@C0HaL
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public void run() UgF)J
{ gi1}5DR
while(nStartPos < nEndPos && !bStop) o|rGy5
{ O\|C,Epm
XV74Fl
s[0prm5.
try{ 9f@#SB_H
URL url = new URL(sURL); 5QqJI#4~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kGB#2J
httpConnection.setRequestProperty("User-Agent","NetFox"); ()+jrrK
String sProperty = "bytes="+nStartPos+"-"; W /~||s
httpConnection.setRequestProperty("RANGE",sProperty); w,M1`RsK
Utility.log(sProperty); JxX jDYrU
0C7thl{Dms
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InputStream input = httpConnection.getInputStream(); .fio<mqi
//logResponseHead(httpConnection); n4ds;N3Hd
|%M{kA-
gE-w]/1zD5
byte[] b = new byte[1024]; O4 +SD
int nRead; yDCooX0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ROJ'-Vde9
{ y9V;IXhDc
nStartPos += fileAccessI.write(b,0,nRead); "ay,Lr
//if(nThreadID == 1) ;a!h.8UJPI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jyY^iQ.2
} cc2d/<:
?`vM#)
*@-q@5r}!
Utility.log("Thread " + nThreadID + " is over!"); 9J-!o]f .b
bDownOver = true; NDs]}5#
//nPos = fileAccessI.write (b,0,nRead); /{eih]`x(
} .LeF|EQU\@
catch(Exception e){e.printStackTrace ();} 9G`FY:(K
} 7$q2v=tH_
} tF#b&za
s8f3i\1
6T{o3wc;
//打印回应的头信息 L]/\C{}k
public void logResponseHead(HttpURLConnection con) buq *abON
{ 4%',scn
for(int i=1;;i++) ~xlMHf
{ +LQs.*
String header=con.getHeaderFieldKey(i); :=iM$_tp'
if(header!=null) W(u6J#2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); I:uQB!
Utility.log(header+" : "+con.getHeaderField(header)); }\PE {
else 'gk81@|
break; zJy 89ib'
} (!XYH@Mz<w
} JR? )SGB
i(&6ys5
'y+bx?3Z
public void splitterStop() e-Ybac%
{ 6g~o3
bStop = true; i-i}`oN
} MrKU,-
^B&ahk
^ RcIE (
} ReHd~G9
\V"PmaP\
07T;IV3#C5
/* uDy>xJ|
**FileAccess.java 9d,]_l.sB
*//文件访问(定位，写) |`q)/ 08b
package NetFox; % L %1g
import java.io.*; iS:PRa1
rr07\;
*Lb(urf
public class FileAccessI implements Serializable{ ^?K?\
2d>d(^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :YRzI(4J
RandomAccessFile oSavedFile; 'n>3`1E,
long nPos; J1c&"Oh
{P<BJ52=
Vav+$l|j@
public FileAccessI() throws IOException f@F^W YQm
{ `:bvuc(
this("",0); ~ ];6hxv
} z`xz~9a<
"j.oR}s9?#
z2s|.M]&-D
public FileAccessI(String sName,long nPos) throws IOException .J1Hg
{ 0ez i?Um
oSavedFile = new RandomAccessFile(sName,"rw"); aoakTi!}
this.nPos = nPos; u':0"5}
oSavedFile.seek(nPos); :m)Rmwn_
} giSG 6'WA
~*cY& 9
nuQLq^e
public synchronized int write(byte[] b,int nStart,int nLen) _#^A:a^e8
{ 'QekQ];
int n = -1; FSYjp{z5
try{ p^zEfLTU
oSavedFile.write(b,nStart,nLen); ,Zcx3C:#
n = nLen; LO$#DHPt
} 3R:7bex
catch(IOException e) 1<qVN'[
{ T`w};]z^d2
e.printStackTrace (); ]=86[A-2N
} vRb(eg
O%++0k;
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return n; QkCoW[sn
} 9i2vWSga
C_^R_
7AtXG^lK
} #Zavdkw=d
/4-eoTxy
c@o/Cv
/* /P8eI3R
**SiteInfoBean.java G$x["
*/ 4}_w4@(
package NetFox; H'= i
xU\:Vid+A
1O3<%T#LOZ
public class SiteInfoBean { O'& \-j 1
1(;33),P8
YI),q.3X~
private String sSiteURL; //Site's URL 9 <kkzy
private String sFilePath; //Saved File's Path C#?d=x
private String sFileName; //Saved File's Name b1>$sPJ+
private int nSplitter; //Count of Splited Downloading File 7dg 5HH
nxh/&%
G`9F.T_Z^)
public SiteInfoBean() IrwF B
{//nSplitter的缺省值为5 /wxxcq
//default value of nSplitter is 5 .IAHy)li"
this("","","",5); LWb}) #E
} CQuvbAo
5W]N]^v
VY&9kN
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u,SX`6%
{ r+#V{oE_
sSiteURL= sURL; {}_Oo%IVGK
sFilePath = sPath; n,Mw# r?y
sFileName = sName; @%@^5
this.nSplitter = nSpiltter; %{VI-CQ
wgR@M[]o;
bd 1J#V]
} L pi_uK
CD<u@l,1
g-V\s&}
public String getSSiteURL() dBq,O%$oq
{ h9n<ped`A;
return sSiteURL; QsF<=b~
} \FY De
^nm!NL{z^
Boj{+rE0
public void setSSiteURL(String value) owY_cDzrH
{ \7tvNa,C
sSiteURL = value; k&"qdB(I
} O7CYpn4<7
xo_k"'f+
+U/"F|M
public String getSFilePath() Lp]C![\>U
{ (uK), *6B
return sFilePath; S| -{wC%
} w>q_8V_K
]aW.b_7<9
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public void setSFilePath(String value) 2Ku#j ('
{ y`@4n.Q
sFilePath = value; B l/e>@M
} z` ?xS
iIEIGQx
~V- o{IA
public String getSFileName() }]GK@nn7
{ 5sCky)N
return sFileName; b!HFv;^N
} ;WAu]C|
>]|^Ux,WZ
dvWlx]'
public void setSFileName(String value) __n"DLW
{ n|,Vm@zV
sFileName = value; MGC0^voe
} EkAqFcKLq
yrYaKh
,v5>sL
public int getNSplitter() &+{xR79+&
{ `IRT w"
return nSplitter; ?&nz
} L#@$Mtc
w>UV\`x
)ZU#19vr7
public void setNSplitter(int nCount) d@4=XSj
{ Fl>j5[kLZ
nSplitter = nCount; ,F9wc<V8
} 4wD^?S!p
} (V?`W7
<gzMDX[^M
~9;mZi1-
/* *7V{yK$O|
**Utility.java VzM@DM]=~
*/ vgZPDf|
package NetFox; ghQsS|)p.
M6Z`Pwv];
acZ|H
public class Utility { J;Xz'0
:*%\i' $!/
D.x3@+
public Utility() CMjPp`rA
{ ][qA@3^Tw
Ip\g^ia
;ypO'
} Yy~Dg
G%/cV?18
//线程睡眠 Y k6WSurw
public static void sleep(int nSecond) RXvcy<
{ g8@HAV^H
try{ )tg*dE
Thread.sleep(nSecond); .shI%'V
} Ds5&5&af
catch(Exception e) #^w 1!xXD
{ +mPB?5
e.printStackTrace (); }slEkpk?]
} @,$HqJ
} @].aFhH`)
|8+rUFkU8
//日志 X KeK;+
public static void log(String sMsg) j*\MUR=
{ Dp'af4+%$
System.err.println(sMsg); ;b2>y>?[
} RaqrVC
2uB26SEIl
Ps,w(k{d
public static void log(int sMsg) t?&ajh
{ *g.,[a0
System.err.println(sMsg); Ase1R=0
} ECfY~qK
} Ok"wec+,
9uo\&,,
F&Z>B};
/* N.J:Qn`(
**TestMethod.java EE{%hGb
*/ sAj$U^Gp
package NetFox; $>`8'I
XwGJ 8&N
t/c^hTT
public class TestMethod { #Z5~a9rO
"lMWSCas
O3^@"IY
public TestMethod() O$\N]#
{ ///xx/weblogic60b2_win.exe L(YT6Vmm+t
try{ 32J
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); FpYoCyD}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v0pEN\
SiteFileFetch fileFetch = new SiteFileFetch(bean); p[IgnO
fileFetch.start(); ba.OjK@
} EH%j$=@X
catch(Exception e){e.printStackTrace ();} *tqeq y-X
g-`NsqzD
Va:jMN
} J#^M
3KZ h?~B
lTNkmQ
public static void main(String[] args) -UE-v
{ c73ZEd+j
new TestMethod(); AS398L
} ijT^gsLL
} ?/g(Y
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