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)); xw}yl4WT{
} v{t pRL0
for(int i=0;i<nEndPos.length-1;i++) hZ*vk
{ wrgB =o
nEndPos = nStartPos[i+1]; }k-8PG =
} ^rO"U[To
nEndPos[nEndPos.length-1] = nFileLength; E#:!&{O
} b.RU%Y#>\
} /Tm+&Jd
?[zw5fUDS
s0;a j<J
//启动子线程 InbB2l4G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `i cs2po
for(int i=0;i<nStartPos.length;i++) GJcxqgk$
{ XH~(=^/_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4bA^Gq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /7#e
nStartPos,nEndPos,i); T^|k`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w=;>
fileSplitterFetch.start(); :Q=y'<
} SgewAng?@o
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z6@8IszU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [?I<$f"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", HP]5"ziA
nEndPos = " + nFileLength); 3{?X>6T
// fileSplitterFetch[nPos.length-1].start(); s2SV
m8{8r>6*
N s0,Z#Z+
//等待子线程结束 ,H+Y1N4W(
//int count = 0; :FI D,
//是否结束while循环 ao9#E"BfM
boolean breakWhile = false; Eej Lso#\
UMRFTwY
/}~=)QHH
while(!bStop) 7yyX8p>
{ 3W[?D8yi)
write_nPos(); ,Kj>F2{
Utility.sleep(500); a)pc+w#
breakWhile = true; Jk(V ]
&Ril[siw
bl a`B=r
for(int i=0;i<nStartPos.length;i++) 7>gjq'0
{ mW'3yM
if(!fileSplitterFetch.bDownOver) mA$y$73=T
{ }Mt)57rU
breakWhile = false; 0)d='3S
break; G7"(,L` 5
} 7ihcjyXB
} rHw#<oV
if(breakWhile) mTtaqo_Bh
break; ;LP3
Wjl2S+Cc
,M{G X
//count++; r'{N_|:vv
//if(count>4) v; i4ZSV^A
// siteStop(); xA7~"q&u
} ;&6 {c
yZNG>1N
o|h=M/
System.err.println("文件下载结束！"); K:'^f? P
} L$_%T
catch(Exception e){e.printStackTrace ();} <<?32r~
} \h=*pAf
\OkZ\!<hg
L#K`F8Wi=
//获得文件长度 vx($o9
public long getFileSize() Og%Y._
{ &j1-Ouy
int nFileLength = -1; i%.NP;Qq]M
try{ R`<2DC>h9
URL url = new URL(siteInfoBean.getSSiteURL()); *1["x;A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kVWcf-f
httpConnection.setRequestProperty("User-Agent","NetFox"); gyAJ#N|
q}L`8(a
nX3?7"v
int responseCode=httpConnection.getResponseCode(); ?lD)J?j
if(responseCode>=400) 1xS+r)_n@
{ /Z?o%/bw:
processErrorCode(responseCode); -V{"Lzrfug
return -2; //-2 represent access is error 7d%x7!E
} 1i$VX|r
7\%JJw6h
%f&Y=
String sHeader; YOLzCnI4
uT,i&
LcvczST
for(int i=1;;i++) ,V!"4T,Z
{ 7u&l]NC?y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \ZADY.ha
//Utility.log(in.readLine()); q&z'S
sHeader=httpConnection.getHeaderFieldKey(i); /lUfxc4
if(sHeader!=null) ;dUKFdKH}
{ nktGO
if(sHeader.equals("Content-Length")) b)'CP Cu*
{ {DP9^hg
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WlQCPC
break; nC,QvV
} b]z_2h~`
} rwXpB<@l@
else 03 gbcNo
break; 50Gr\
} 7uc\AhOk6
} W !j-/ql
catch(IOException e){e.printStackTrace ();} 7mYcO3{5{
catch(Exception e){e.printStackTrace ();} +^(_S9CO
-(?/95 Y
@-[}pZ/
Utility.log(nFileLength); 9#U]?^DJ@
qzNb\y9G
Jyg1z,B <
return nFileLength; ?SgFD4<~P
} WeRDaG
#d$zW4ur2
GalSqtbmDt
//保存下载信息（文件指针位置） gNP1UH4m
private void write_nPos() Z(|$[GZP[
{ nm#23@uZ4K
try{ WRu(F54Sk
output = new DataOutputStream(new FileOutputStream(tmpFile)); bgBvzV&'8
output.writeInt(nStartPos.length); 0,RYO :`
for(int i=0;i<nStartPos.length;i++) 5@>hjXi"Y
{ r2\%/9uO
// output.writeLong(nPos); r]cq|Nv8:
output.writeLong(fileSplitterFetch.nStartPos); hOk9y=
output.writeLong(fileSplitterFetch.nEndPos); Rw0|q
} <J+Oh\8tad
output.close(); rd0Fd+t/
} CA igV$
catch(IOException e){e.printStackTrace ();} ^/E'Rf3[A
catch(Exception e){e.printStackTrace ();} ^AU-hVj
} trrNu
b>p_w%d[[J
-y!Dg6A
//读取保存的下载信息（文件指针位置） ,V 52Fj
private void read_nPos() THQ #zQ-
{ DDR4h"Y
try{ 3@x[M?$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L@T/4e./
int nCount = input.readInt(); Kt*b) <
nStartPos = new long[nCount]; :'wxm3f
nEndPos = new long[nCount]; A)9]^@,
for(int i=0;i<nStartPos.length;i++) ]pe7I P
{ wnd #J `
nStartPos = input.readLong(); (LTu=1
nEndPos = input.readLong(); 8m' f8.x
} x`7Le&4f
input.close(); ":+d7xR?o
} </_QldL_
catch(IOException e){e.printStackTrace ();} wX)'1H):T
catch(Exception e){e.printStackTrace ();} zNo,PERG
} V.`hk^V,
J&\Q3_vro9
\wz^Z{U
private void processErrorCode(int nErrorCode) ! N2uJ?t
{ ^}$t(t
System.err.println("Error Code : " + nErrorCode); >4wigc
} i/_rz.c~3
f91]0B`C
>mA]2gV<a
//停止文件下载 TW&s c9
public void siteStop() #\X)|p2
{ }bw^p.ci
bStop = true; -S]ercar
for(int i=0;i<nStartPos.length;i++) k0j4P^d
fileSplitterFetch.splitterStop(); A nl1+
]*a(^*}A%
0O'M^[=d.8
} hJ8&OCR }
} kXhd]7ru
//负责部分文件的抓取 Y_n/rD>
**FileSplitterFetch.java m_Hg!Lg
*/ c$[2tZ
package NetFox; ]g$ky.;
2&S^\kf
~`e!$=
import java.io.*; ' u<IS/w
import java.net.*; +$ djX=3
6,LE_ -G5
XixjdBFP
public class FileSplitterFetch extends Thread { am/}V%^
xS@jV6E~
(^B1Kt!<
String sURL; //File URL prS%lg>
long nStartPos; //File Snippet Start Position e^q^AP+*
long nEndPos; //File Snippet End Position Pn4.gabE
int nThreadID; //Thread's ID z@IG"D
boolean bDownOver = false; //Downing is over 2*`kkS
boolean bStop = false; //Stop identical P51cEhf
FileAccessI fileAccessI = null; //File Access interface FYik}wH]
7<70\6
5,XEN$^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *.w6=}
{ a+z>pV|
this.sURL = sURL; p\_3g!G'
this.nStartPos = nStart; 2|ee`"`
this.nEndPos = nEnd; X n0HJ^"_
nThreadID = id; xp:I(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z<t2yh(DF
} V8F!o
Oq<3&*
!8|r$mN8
public void run() 'uz o[>p
{ R $<{"b
while(nStartPos < nEndPos && !bStop) 5D/Td#T04
{ ;ja~Q .}4
oD2! [&
W="pu5q$5
try{ rJf{YUZe
URL url = new URL(sURL); a++gwl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V+sZ;$
httpConnection.setRequestProperty("User-Agent","NetFox"); nO6UlY
String sProperty = "bytes="+nStartPos+"-"; 2va[= >_
httpConnection.setRequestProperty("RANGE",sProperty); p?Ux1S
Utility.log(sProperty); qYe`</
.DwiIr'
s'tXb=!HO
InputStream input = httpConnection.getInputStream(); H{E(=S
//logResponseHead(httpConnection); tAjT-CXg
PQ!'<
"(H%m9K
byte[] b = new byte[1024]; Fi+DG?zu
int nRead; G$*=9`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jm&[8ApW
{ |;V-;e*
nStartPos += fileAccessI.write(b,0,nRead); ,>(X}Q
//if(nThreadID == 1) zuMz6#aCC8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ByoI+n* U
} -[>J"l
sDgo G
ec^{ez@`
Utility.log("Thread " + nThreadID + " is over!"); y<IHZq`C3
bDownOver = true; L6qK3xa}
//nPos = fileAccessI.write (b,0,nRead); L1lDDS#
} E}w5.1
catch(Exception e){e.printStackTrace ();} ;gHcDnH)
} LmsPS.It
} Qj [p/H$
JUGq\b&m
0"@J*e#
//打印回应的头信息 QN#Lbsd
public void logResponseHead(HttpURLConnection con) ?zsRs?rc0
{ , =*^XlO=c
for(int i=1;;i++) 7dB_q}<
{ A Ef@o+A
String header=con.getHeaderFieldKey(i); ]_s;olKNI
if(header!=null) HIj:?y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Y._ACQG3
Utility.log(header+" : "+con.getHeaderField(header)); Qe7 SH{
else o^uh3,.
break; Ia9!ucN7DA
} h+q#|N
} (u8OTq@
Wvd-be
&2y9J2aA
public void splitterStop() OI/]Y7D[Oq
{ IO?a.L:6U
bStop = true; g~|x^d^;|
} =<M>fJ)
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bjj F{T
} Ub\&k[F
m=pH G
ept:<!4
/* TgRG6?#^l
**FileAccess.java DB jUHirK
*//文件访问(定位，写) Q[`2?j?
package NetFox; .Xxxz Wyk
import java.io.*; "AWk jdj
&8%^o9sH
ex|)3|J
public class FileAccessI implements Serializable{ a(JtGjTf&
y </i1qM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CpgaQG^
RandomAccessFile oSavedFile; Ym]rG 4
long nPos; !"08TCc<
guy!/zQ>A
@[/!e`]+
public FileAccessI() throws IOException Vhm^<I-d
{ sdewz(xskj
this("",0); v<0S@9~
} +tlbO?
nu|?F\o!
*:l$ud
public FileAccessI(String sName,long nPos) throws IOException HW6Cz>WxOW
{ 8,CL>*A
oSavedFile = new RandomAccessFile(sName,"rw"); 0eCjK.
this.nPos = nPos; v!mP9c j
oSavedFile.seek(nPos); eEmLl(Lb
} -42 U
lvk*Db$
4uVyf^f\]f
public synchronized int write(byte[] b,int nStart,int nLen) -x/g+T-
{ ~F~hgVS5
int n = -1; ov>`MCS,v
try{ ,b+Hy`t
oSavedFile.write(b,nStart,nLen); ws]d,]
n = nLen; BIvz55g
} Y(R],9h8
catch(IOException e) `lO/I+8
{ Y k"yup@3
e.printStackTrace (); +@rc(eOwvN
} V/"41
;ZrFy=Iv
5kv]k?
return n; q 7+|U%!9
} yg4ILL
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M?$tHA~OX
} 52 DSKL
.9!&x0;
*EtC4sP
/* Gg7ZSB 7
**SiteInfoBean.java =\<!kJ\yH
*/ OBPiLCq
package NetFox; twTRw:.!f
cja-MljD
{\=NZ\
public class SiteInfoBean { r2Q) Q
Lhgs|*M
g{7?#.7
private String sSiteURL; //Site's URL ><@& &u.
private String sFilePath; //Saved File's Path 69C ss'
private String sFileName; //Saved File's Name qkyYt#4E
private int nSplitter; //Count of Splited Downloading File abV,]x&.0
7aNoqS+
%A(hmC
public SiteInfoBean() ]<O-
{//nSplitter的缺省值为5 A5dH*< }
//default value of nSplitter is 5 gm&O-N"=U
this("","","",5); iB'g7&,L
} O{G $]FtF
Fg^zz*e
[ **F
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %{P." ki
{ -| t|w:&
sSiteURL= sURL; v-Uz,3
sFilePath = sPath; bNz2Uo!0K
sFileName = sName; e}"k8 ./
this.nSplitter = nSpiltter; 1]jUiX=T
E!>l@ ki
6HR*)*>z_
} ]h&?^L<.
M$LzV}k
QjUojHz%Z
public String getSSiteURL() ;W#/;C _h
{ '#8;bU
return sSiteURL; AzBpQb*
} c6pGy%T-
S4X['0rX!
7otqGE\2
public void setSSiteURL(String value) ["?WVXCF8|
{ c\eT`.ENk
sSiteURL = value; u]Y NF[]
} +&TcTu#.`
CW#$%
:!gzx n
public String getSFilePath() t~]oJ5%
{ %^8>=
return sFilePath; 6I\mhw!pQ
} |=}v^o ZC
"LH*T
Fqp~1>wi
public void setSFilePath(String value) \A3yM{G~+
{ 8uhB&qxB
sFilePath = value; vR\[IV?
} _b 8XF&O
Hz<)a(r!J
_N`pwxpsb
public String getSFileName() =E%<"FB
{ =R\-mov$
return sFileName; ku=XPmZ.\
} qxW2q8QHo
bYH! P/
/-)|dP
public void setSFileName(String value) -`ykVHgg
{ U^X8{,8O
sFileName = value; -?<L"u
} 5Bc)QKh`l|
=!Y{Mz
/%GMbO_
public int getNSplitter() OL"So u4
{ KbV%8nx!!
return nSplitter; zoBjrAyD
} >'zp
%4E7 Tu,1
Ycx$CUC
public void setNSplitter(int nCount) 0#KB.2AP
{ D+ **o
nSplitter = nCount; M+TF0c
} ~d?\rj3=
} 4==LtEp
xR;-qSl7Ms
Swz1RT
/* 5Gsj;
**Utility.java 0Z{(,GU
*/ U!x\oLP
package NetFox; QcQ|,lA.HI
;EfMTI}6K
KPA5 X]
public class Utility { MXhRnVz"W
B1Iq:5nmoS
VI`x fmVOQ
public Utility() way-Q7
{ X_eV<]zA+
|"Oazll
MPd#C*c
} \:?H_^^d
G1'w50Yu
//线程睡眠 a[8_O-
public static void sleep(int nSecond) @]h#T4z'
{ AH],>i3
try{ *H RxC
Thread.sleep(nSecond); @*O(dw
} uL4@e
catch(Exception e) 4.dMNqU
{ jWW2&cBm\
e.printStackTrace (); L3~E*\cV
} .ODtduURe
} =;$&:Zjy/%
kB]|4CG{
//日志 n%<.,(.(S
public static void log(String sMsg) zj;y`ENj
{ )V}u1C-N
System.err.println(sMsg); i9M6%R1m}E
} m%E7V{t
,O(XNA(C
U%45qCU
public static void log(int sMsg) LVLh&9
{ j{P,(-
System.err.println(sMsg); :7!/FBd
} 8LwbOR"
} 9H3#8T] ;
sEvJ!$Tt?I
1.H"$D>TC
/* Phgn|
**TestMethod.java ]@ [=FK^
*/ N]yk<55
package NetFox; _L!"3
M=N`&m\
"5jZS6A]
public class TestMethod { sinG $=
nhCB])u8l
a4: PufS
public TestMethod() *G~c6BZ
{ ///xx/weblogic60b2_win.exe d*>M<6b-
try{ z4J-qK~2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |ns^'q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Qw5M\
SiteFileFetch fileFetch = new SiteFileFetch(bean); C.(ZXU7
fileFetch.start(); ]-fZeyY$
} V`WfJ>{;Z
catch(Exception e){e.printStackTrace ();} y~S[0]y>
ypd
FJL9x,%6
} sfrh+o57
6y5arP*6e
{2:H`|x
public static void main(String[] args) %r!#
{ H[Pb Wy:
new TestMethod(); puqH%m+u
} BkqIfV%O
} E>6zwp
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