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)); NRHr6!f>
} ,u?wYW;
for(int i=0;i<nEndPos.length-1;i++) >}dTO/
{ Gs_*/E7,
nEndPos = nStartPos[i+1]; Lo|NE[b:G
} S{^6iR
nEndPos[nEndPos.length-1] = nFileLength; TdNuD V
} Xb(CH#*{z
} w&wA >q>&
q9>Ls-k
b!4N)t>gl
//启动子线程 2d5}`>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #sz]PZ\
for(int i=0;i<nStartPos.length;i++) 2A*X Hvwb
{ )Y&MIJ7>@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;xW8Z<\-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #Dj"W8'zh
nStartPos,nEndPos,i); ?Kx6Sf<i
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 95.qAFB1
fileSplitterFetch.start(); cW81
} 8X}^~e
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p|&ZJ@3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $'A4RVVT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", iX8h2l
nEndPos = " + nFileLength); a' IX yj
// fileSplitterFetch[nPos.length-1].start(); m%e^&N#%6r
KXoL,)Hl
'h!h!
//等待子线程结束 ULp)T`P
//int count = 0; 9]]!8_0=r
//是否结束while循环 7af?E)}v
boolean breakWhile = false; V]l&{hl,
t7jh?]
@!z$Sp=
while(!bStop) 8BYIxHHz
{ .DgoOo%?"
write_nPos(); e={k.y}x}
Utility.sleep(500); 7.wR"1p#
breakWhile = true; wFK:Dp_^
MuDFdbtR
nwa\Lrh
for(int i=0;i<nStartPos.length;i++) ;yk9(wea}"
{ @wd!&%yzO
if(!fileSplitterFetch.bDownOver) V+qFT3?-
{ y;,=ajrF
breakWhile = false; EzzTJ>
break; O{lIs_1.Z
} 8yHq7=
} qiG]nCq
if(breakWhile) mV6#!_"
break; a(PjcQ4dY
ePV-yy
G*kE~s9R
//count++; bWGyLo,
//if(count>4) 6@"Vqm|HD
// siteStop(); Si#"Wn?|
} o\_ Td
X4d Xm>*?=
Pk$}%;@v
System.err.println("文件下载结束！"); W0VA'W
} D3<IuWeM
catch(Exception e){e.printStackTrace ();} fC=fJZU7$
} <T(s\N5B=
=}~NRmmF
I["F+kt^^
//获得文件长度 [:AB$l*
public long getFileSize() 5Z* b(R
{ |$YyjYK
int nFileLength = -1; m(2G*}
try{ \w{@u)h
URL url = new URL(siteInfoBean.getSSiteURL()); fUb1/-}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,]0S4h67
httpConnection.setRequestProperty("User-Agent","NetFox"); 17e=GL
l_^T&xq8
Oamv9RyDvC
int responseCode=httpConnection.getResponseCode(); 4 hL`=[AB
if(responseCode>=400) zt7_r`#z
{ hNH.G(l0
processErrorCode(responseCode); x7vq?fP0n
return -2; //-2 represent access is error XxmJP5
} "nVK< Vd
aXRv}WO$>k
+n@f'a">
String sHeader; /)sDnJ1r
* eA{[
zl0;84:H
for(int i=1;;i++) t[%x}0FP-F
{ ^Ku\l #B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q]F4Lq(
//Utility.log(in.readLine()); EYA/CI
sHeader=httpConnection.getHeaderFieldKey(i); x$~3$E
if(sHeader!=null) U'rr?,RML
{ A|2 <A !
if(sHeader.equals("Content-Length")) IeO-O'^&`
{ =Nw2;TkB[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9TqoLX
break; #]?tY}~
} ^Y$QR]
} pI &o?n
else 2K3MAd{
break; J cP~-cp
} BTOA &Ag
} 0Xp nbB~~I
catch(IOException e){e.printStackTrace ();} %_>Tcm=
catch(Exception e){e.printStackTrace ();} -oU@D
Ynvj;
| @uq()
Utility.log(nFileLength); DYc.to-
Y [4vRzc
4S'[\ZJO
return nFileLength; E3y6c)<
} `+oV/:Q3
Ud$Q0m&
DG3[^B
//保存下载信息（文件指针位置） D`en%Lf!m
private void write_nPos() |pBMrN+is
{ +-U@0&Y3M
try{ pQqbZ3]
output = new DataOutputStream(new FileOutputStream(tmpFile)); xtOx|FkYcl
output.writeInt(nStartPos.length); I=U+GY:
for(int i=0;i<nStartPos.length;i++) l(gJLjTH%
{ 3QIdN
// output.writeLong(nPos); l`DtiJ?$$0
output.writeLong(fileSplitterFetch.nStartPos); Y=9qJ`q
output.writeLong(fileSplitterFetch.nEndPos); F@<O;b#Ip
} dl:-k r8
output.close(); it~Z|$
} 5bXHz5i
catch(IOException e){e.printStackTrace ();} :]yg
catch(Exception e){e.printStackTrace ();} `Uv)Sf{
} tzPC/?
)Ea8{m!
Hc M~
//读取保存的下载信息（文件指针位置） [ne" T
private void read_nPos() +)zDA:2Wa"
{ Yhe+u\vGs\
try{ "2%>M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); sA3UeTf
int nCount = input.readInt(); k'g$2
nStartPos = new long[nCount]; p<q].^M
nEndPos = new long[nCount]; F%Kp9I*
for(int i=0;i<nStartPos.length;i++) NaF(\j
{ U7E
nStartPos = input.readLong(); r?\|f:M3
nEndPos = input.readLong(); )AJ=an||5
} lw s(/a*c
input.close(); {$0&R$v3
} `%oIRuYG]j
catch(IOException e){e.printStackTrace ();} =rEA:Q`~w
catch(Exception e){e.printStackTrace ();} @^'$r&M
} `YU=~xQ
2yvVeo&3
&-=K:;x
private void processErrorCode(int nErrorCode) "NKf0F
{ {8 N=WZ
System.err.println("Error Code : " + nErrorCode); x)3~il5
} Vg{Zv4+t
p!}ZdX[u
mW~P!7]
//停止文件下载 U_l7CCK +
public void siteStop() pr$~8e=c
{ D;jK/2
bStop = true; #MglHQO+
for(int i=0;i<nStartPos.length;i++) Ge^Qar
fileSplitterFetch.splitterStop(); @ ICbKg:
0Qp[\ia
Fom>'g*
} Z["BgEJ
} Pr`s0J%m
//负责部分文件的抓取 p-,Iio+
**FileSplitterFetch.java S.W^7Ap
*/ ck$M(^)l
package NetFox; v77fQ0w3
ZjS(ad*.2
/=TH08
import java.io.*; FN!1|'VK
import java.net.*; '#W_boN
x#mtS-sw2Q
>fH*XP>(
public class FileSplitterFetch extends Thread { Yy hny[fa9
0cFn{q'u
N xFUO0O3
String sURL; //File URL @(>XOj?+
long nStartPos; //File Snippet Start Position c" +zgP
long nEndPos; //File Snippet End Position #]y5zi
int nThreadID; //Thread's ID O#:&*Mv
boolean bDownOver = false; //Downing is over =JW[pRI5a
boolean bStop = false; //Stop identical ' S,2
FileAccessI fileAccessI = null; //File Access interface &{ZSE^
R*bmu
B)6#Lp3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t.)AggXj#
{ {fU?idY)c
this.sURL = sURL; qp&4 1
this.nStartPos = nStart; y(}Eko4u5
this.nEndPos = nEnd; \2>?6zs
nThreadID = id; nvt$F%+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h>klTPM>
} ZdH1nX(Yh3
_B[WY
8_a3'o%5
public void run() Jq)U</
{ /H)Br~ l
while(nStartPos < nEndPos && !bStop) a+Ab]m8`
{ 63M=,0-Qt
DsGI/c
ertBuU
try{ 5un^yRMB-
URL url = new URL(sURL); @5E,:)T*wR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^N-'xy
httpConnection.setRequestProperty("User-Agent","NetFox"); j5^-.sEEw
String sProperty = "bytes="+nStartPos+"-"; b#a@rh
httpConnection.setRequestProperty("RANGE",sProperty); ,r`UBQ}?
Utility.log(sProperty); X;VQEDMPU
OH6n^WKY
DP*@dFU"
InputStream input = httpConnection.getInputStream(); O%g\B8;
//logResponseHead(httpConnection); [zh"x#AyI
"Pj}E=!k
\$pkk6Q3,w
byte[] b = new byte[1024]; Qqq <e
int nRead; 8TPN#"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zCV7%,H~
{ Qxt@V
nStartPos += fileAccessI.write(b,0,nRead); `!i-#~n
//if(nThreadID == 1) [/$N!2'5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RJ}#)cT
} wkBL=a
3?`"
N4wA#\-
Utility.log("Thread " + nThreadID + " is over!"); =~jAoOC@
bDownOver = true; <2<87PU
//nPos = fileAccessI.write (b,0,nRead); pbLGe'
} ;#/0b{XFj
catch(Exception e){e.printStackTrace ();} S GM!#K
} 78]gtJ
} &{z<kmc$6
P^i.La,
E\$C/}T
//打印回应的头信息 S_\ F
public void logResponseHead(HttpURLConnection con) &z@~B&O
{ nIBFk?)6
for(int i=1;;i++) >qh?L#Fk
{ F8=nhn
String header=con.getHeaderFieldKey(i); c!wtf,F
if(header!=null) 6ep>hS4A&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Fm3t'^SqF
Utility.log(header+" : "+con.getHeaderField(header)); !9 f4R/ ?
else c-8!#~M(
break; 8\Hr5FqB(
} wC` R>)
} 1mH\k5xu
2"&)W dm
zOB=aG?/
public void splitterStop() A'-_TFwW
{ Ik~1:D]f
bStop = true; Fn+?u
} v}[dnG
\#6Fm_b]u
,}J_:\j
} euQ.ArF
e:-8k_0|
d,9`<1{9
/* 8l>CR#%@C
**FileAccess.java &y\sL"YL!
*//文件访问(定位，写) s'u(B]E
package NetFox; &`Ck
import java.io.*; X?o( b/F-
4c159wsnQ
,Z~;U
public class FileAccessI implements Serializable{ hfrnxeM#~
C@gXT]Q 0}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 qp~gP
RandomAccessFile oSavedFile; >/^#Drwb!i
long nPos; ;t(f1rPyE
qf8[!5GM
S$[k Q|Am
public FileAccessI() throws IOException 0rE(p2
{ rU2iy"L
this("",0); kWW w<cA
} F L=,YP
6`\ya@
Cifd21v4
public FileAccessI(String sName,long nPos) throws IOException I%lE;'x
{ -]S.<8<$
oSavedFile = new RandomAccessFile(sName,"rw"); G>z,#Xt
this.nPos = nPos; ,Em$!n
oSavedFile.seek(nPos); .}`hCt08
} _*6v|Ed?
k\7:{y@,
Q+$Tt7/
public synchronized int write(byte[] b,int nStart,int nLen) %y<]Yzv.
{ jirbUl
int n = -1; #A<P6zJXR
try{ H0*,8i5I
oSavedFile.write(b,nStart,nLen); @pza>^wk
n = nLen; JPx7EEkZR4
} ;#k-)m%
catch(IOException e) q/gB<p9
{ G/?~\ }:s
e.printStackTrace (); R,_d1^|*w
} w4:\N U
{nMAm/kyj
Es'Um,ku
return n; XFqJ 'R
} =A!S/;z>
[L~@uAMw:
K%j&/T j1
} vO@s$qi
-kj< 1~YW
^TFs;|..
/* d- E4~)Qy
**SiteInfoBean.java 9NpD!A&64<
*/ `a]44es9q
package NetFox; Nt-<W+,
lmCZ8 j(FF
Bl;KOR
public class SiteInfoBean { Z)"61) )
t+TYb#Tc
`\Unpp\I
private String sSiteURL; //Site's URL s8gU7pT49
private String sFilePath; //Saved File's Path 0b|zk <
private String sFileName; //Saved File's Name >G"X J<IO
private int nSplitter; //Count of Splited Downloading File Y}STF
cO#oH2}
*r,b=8|
public SiteInfoBean() \fLvw
{//nSplitter的缺省值为5 wts:65~
//default value of nSplitter is 5 +cB&Mi5
this("","","",5); >cR)?P/o
} 3OqX/z,
XvGA|Ekf<
uB.-t^@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^]c6RE_
{ tj1JB%
sSiteURL= sURL; ` %?9=h%
sFilePath = sPath; >^_ bD
sFileName = sName; 8;\sU?
this.nSplitter = nSpiltter; 2WBq
H7g< p"
!u;>Wyd W
} i+vsp@d
u<tk G B
; y.E!
public String getSSiteURL() 'cdN3i(
{ Iw=Sq8
return sSiteURL; }nx=e#[g%2
} I$q>
*OTS'W~t
o'V%EQ
public void setSSiteURL(String value) Q9?t[ir
{ m7|RD]q&
sSiteURL = value; ((3}LQ
} ^4$'KIq
cPF<D$B
;[0&G6g
public String getSFilePath() C2F0tr|
{ #gbH^a'
return sFilePath; 2y GOzc
} i%{X9!*%TX
.p6+l!"
f@V3\Z/6E
public void setSFilePath(String value) a}nbo4jK
{ Y:QD
sFilePath = value; O>0VTW
} `)>7)={
: mGAt[Cc
'/%zi,0
public String getSFileName() UVuDQ
{ )mcEQ-!b
return sFileName; fys
} ]F*3"y?)2
^HA %q8| n
X]*QUV]i
public void setSFileName(String value) |;vi*u
{ oR#:NtX@
sFileName = value; '\DSTr:N
} HeN~c<NuB
P&A|PY,P
L\aBc}
public int getNSplitter() v:_B kHN'
{ l:(Rb-Wy
return nSplitter; iZ,YxN<R
} 6tjcAsV
4&^9Wklj
j .A6S`
public void setNSplitter(int nCount) p9ZXbAJ{
{ 7S^""*Q^
nSplitter = nCount; c'fSu;1
} 1&)_(|p[C
} :Ao!ls'=
@1RP/y%
l5t2\Fl
/* Ss?CfRM
**Utility.java :VA.QrKW
*/ M^madx6`
package NetFox; _GtBP'iN
# '|'r+
9ptFG]lZ
public class Utility { .V'V:;BE%
A7XnHPIw
QDmYSY$
public Utility() #=e;?w
{ JqUADm
&Vk; VM`5
=H5\$&xj4.
} alFjc.~}
c@m5~
//线程睡眠 ub?K,
public static void sleep(int nSecond) hq>Csj==@
{ g=)J~1&p
try{ 72db[
Thread.sleep(nSecond); n]!fO 6kj
} mryN}
catch(Exception e) $6>?;
{ L):qu
e.printStackTrace (); LxN*)[Wb
} 4/>Our 5
} 2s ,8R
$So%d9k
//日志 +{`yeZ9S
public static void log(String sMsg) w=b(X q+:
{ XAOak$(j
System.err.println(sMsg); @Cq? :o<
} L):U"M>]=
4g _"ku
Lm)\Z P+W
public static void log(int sMsg) 5MxL*DB=b
{ @$@mqHI}
System.err.println(sMsg); %,*$D}H
} 3NK ^AaTK
} =(r* 5vd
$6f\uuTU2"
=H]F`[B=
/* vxlOh.a|/L
**TestMethod.java wzcai 0y*
*/ USML~]G z
package NetFox; v[k5.\No
\&xl{64
JQKdW
public class TestMethod { V2&^!#=s
**_&i!dtL
")#<y@Rv
public TestMethod() ak:v3cQR
{ ///xx/weblogic60b2_win.exe <|6%9@
try{ 0&Gl@4oZ"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !3&kQpF
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8|1^|B(l
SiteFileFetch fileFetch = new SiteFileFetch(bean); Eh8Pwt7C@
fileFetch.start(); 2h~-
} =ZYThfAEw
catch(Exception e){e.printStackTrace ();} #G^A-yjn
B~WtZ-%%E
Dma.r
} `\$8`Zb;
pNaiXu3
Y0uvT7+[hi
public static void main(String[] args) VAQ)Hc]
{ [.yJV`
new TestMethod(); =5]n\"/
} ?^!,vh
} yOXO)u1n
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