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)); r("7 X2f
} G-,PsXSwe
for(int i=0;i<nEndPos.length-1;i++) 73N%_8DH
{ |L]dJ<
nEndPos = nStartPos[i+1]; %}$6#5"';
} @X4;fd
nEndPos[nEndPos.length-1] = nFileLength; &TC
} I0OsaX'
} -4GSGR'L&y
I`5MAvP
%>24.i"l
//启动子线程 n,xK7icYNQ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <_42h|-
for(int i=0;i<nStartPos.length;i++) W>1\f0'
{ ?:H9xJ_^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Rzb663d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #Oe=G:+A
nStartPos,nEndPos,i); C'zMOR6c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A.z~wu%(
fileSplitterFetch.start(); :()4eK/\
} "gK2!N|#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Kz^aW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &;%+Hduc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k$I[F<f
nEndPos = " + nFileLength); BDB-OJ
// fileSplitterFetch[nPos.length-1].start(); CWC*bkd5a
)FU4iN)ei
u# %7>=
//等待子线程结束 egP3q5~
//int count = 0; EaP#~x
//是否结束while循环 EDnmYaa)dZ
boolean breakWhile = false; tgrQ$Yjk
MTLcLmdO
BE3~f6 `
while(!bStop) e=2;z
{ {]Lc]4J
write_nPos(); Dvx"4EA{7{
Utility.sleep(500); 4["}U1sG
breakWhile = true; ytAhhwN~
ym${4
RNi&OG(
for(int i=0;i<nStartPos.length;i++) 9&2kuLp?P
{ />f`X+d
if(!fileSplitterFetch.bDownOver) QQrvT,]
{ y()#FRp7
breakWhile = false; | sQ5`lV?
break; "bw4{pa+
} :uI}"Bp
} q<;9!2py
if(breakWhile) @${!C\([1
break; ;9prsvf
jj.yB#T
uIWCVR8`Y
//count++; 67n1s
//if(count>4) Ebq5P$
// siteStop(); .Qi`5C:U
} 3$y]#L
b LxV
*qq%)7
System.err.println("文件下载结束！"); {8UBxFIM(
} 1p{\jCi,2
catch(Exception e){e.printStackTrace ();} AE<AEq
} B!8]\D
2+Fq'!
QY{f=
//获得文件长度 V;)'FJ)]
public long getFileSize() ]jy6C'Mp
{ 1x\%VtO>\b
int nFileLength = -1; #G]s.by('
try{ \!631FcQ
URL url = new URL(siteInfoBean.getSSiteURL()); }K&K{ 9}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qp-nr]
httpConnection.setRequestProperty("User-Agent","NetFox"); i#Wl?(-i
bu$5gGWVf
9|OQHy
int responseCode=httpConnection.getResponseCode(); *1>XlVx,
if(responseCode>=400) 0<o#;ZQ]
{ 0"<gg5
processErrorCode(responseCode); xorFz{
return -2; //-2 represent access is error (-~tb-
} w|RG
#xts*{u-#
blS*HKw
String sHeader; <27e7H*6
(s"_NUj6
tfdP#1E
for(int i=1;;i++) R;,&CQUl
{ g3Ff<P P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w0Us8JNGz
//Utility.log(in.readLine()); Gz6FwU8L
sHeader=httpConnection.getHeaderFieldKey(i); ?+dI/jB4X
if(sHeader!=null) Q}]Q0'X8
{ m2N ?Fg
if(sHeader.equals("Content-Length")) ;2bG-v'4vO
{ /'ybl^Km
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;9;.!4g/T
break; -|V@zSKr3
} kQ4%J,7e4
} 6!+"7r6
else A03PEaZO
break; "\> <UJ
} m;[z)-&"
} Z1q'4h=F.
catch(IOException e){e.printStackTrace ();} 5"@<7/2qI
catch(Exception e){e.printStackTrace ();} F,4Q
7p2x}[ .\
&_!BMzp4
Utility.log(nFileLength); s$`evX7D
UpB7hA
BHU(Hd
return nFileLength; }g(aZ
} VsUEp_I
,g^Bu{?
oYOf<J
//保存下载信息（文件指针位置） ^\_`0%`>
private void write_nPos() #JTi]U6`
{ 3,iL#_+t
try{ y ?Q"-o (
output = new DataOutputStream(new FileOutputStream(tmpFile)); e2Xx7*vS
output.writeInt(nStartPos.length); r+ vtKb
for(int i=0;i<nStartPos.length;i++) {feS-.Khv
{ S,Oy}Nv
// output.writeLong(nPos); ztb2Ign<
output.writeLong(fileSplitterFetch.nStartPos); 36lIV,YnU
output.writeLong(fileSplitterFetch.nEndPos); '8%aq8
} cL=P((<K?
output.close(); MRmz/ZmRM
} 5%G++oLXf
catch(IOException e){e.printStackTrace ();} 9>zN27
catch(Exception e){e.printStackTrace ();} t,MK#Ko
} @W^g(I(w
*~fN^{B'!
BRH:5h
//读取保存的下载信息（文件指针位置） u5idH),<
private void read_nPos() GW}KmTa]&
{ \ iP[iE=
try{ 0BE%~W
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x<= ;=893
int nCount = input.readInt(); 2RM1-j ($
nStartPos = new long[nCount]; nP0}vX)<
nEndPos = new long[nCount]; s fti[
for(int i=0;i<nStartPos.length;i++) 8vUP{f6{
{ vTB*J,6.
nStartPos = input.readLong(); fM2[wh@
nEndPos = input.readLong(); ([$F5 q1TR
} JWxPH5L
input.close(); gc(1,hv
} Xe+Hez,
catch(IOException e){e.printStackTrace ();} XK&#K? M
catch(Exception e){e.printStackTrace ();} Jl^oDW
} :I&iDS>u1
^?juY}rZ=|
[;X YT
private void processErrorCode(int nErrorCode) fA+M/}=
{ ,e>ugI_;*
System.err.println("Error Code : " + nErrorCode); zV2c`he%z
} T;FzKfT|
`zep`j&8^
3K#e]zoI
//停止文件下载 P-vA.7
public void siteStop() 2QBtwlQ?[
{ JG4&eK$-
bStop = true; -7+Fb^"L
for(int i=0;i<nStartPos.length;i++) s"Kp+tTWj
fileSplitterFetch.splitterStop(); "= %-
o/&:w z
%/>_o{"hw
} bUWtlg
} '.^JN@
//负责部分文件的抓取 rP3)TeG6
**FileSplitterFetch.java C6,Bqlio
*/ Dd{{d?;B
package NetFox; vhUuf+P*
Ads^y`b
&V2G<gm0
import java.io.*; 61C&vm
import java.net.*; PH=wPft
q$HBPR4h
'dht5iI;Yw
public class FileSplitterFetch extends Thread { '7=*n_l
wicg8[T=B
WK<pZ *x
String sURL; //File URL 82w<q(
long nStartPos; //File Snippet Start Position ;N,7#l|wi
long nEndPos; //File Snippet End Position Q2#)Jx\6!
int nThreadID; //Thread's ID CiMN J
boolean bDownOver = false; //Downing is over Z`:V~8=l
boolean bStop = false; //Stop identical 3g6R<Ez
FileAccessI fileAccessI = null; //File Access interface Ep'C FNbtW
'i@Y #F%D
q|6lw 74`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,Y&kW'2
{ 4frZ .r;V
this.sURL = sURL; O=+C Kx@
this.nStartPos = nStart; Z2LG/R
this.nEndPos = nEnd; ).vdKNzw
nThreadID = id; MZ+"Arzb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jwE<}y I
} u{_T,k<!
Cf10 ud
T8RQM1D_s
public void run() ricDP 9#a
{ BE m%x0y
while(nStartPos < nEndPos && !bStop) }ShZ4 xMz
{ Zwq_&cJK
1o$<pZZ
I)sCWC:Mq~
try{ -MU^%t;-
URL url = new URL(sURL); c8u&ev.U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WIbU^WJ0
httpConnection.setRequestProperty("User-Agent","NetFox"); ME7JU|@Z
String sProperty = "bytes="+nStartPos+"-"; t;? q#!uc
httpConnection.setRequestProperty("RANGE",sProperty); T0Gu(c`1d
Utility.log(sProperty); }2{%V^D)r
z?K+LTf8
?=fJu\;
InputStream input = httpConnection.getInputStream(); N8!B2uPQ
//logResponseHead(httpConnection); S[%86(,*gP
L1J"_.=P
dpE+[O_
byte[] b = new byte[1024]; A\?O5#m:$
int nRead; .E@yB`AR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !e%#Zb MIo
{ 2R)Y}*VX
nStartPos += fileAccessI.write(b,0,nRead); YoahqXR`
//if(nThreadID == 1) oinF<-(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `4$" mO>+
} 4w\')@`[jk
g#H#i~E^
0z%]HlPg
Utility.log("Thread " + nThreadID + " is over!"); 3ldOOQW%
bDownOver = true; q3 9RD
//nPos = fileAccessI.write (b,0,nRead); 8_:jPd!3
} !,I}2,1%k
catch(Exception e){e.printStackTrace ();} B` n!IgF8
} 7$/ O{GBJ
} 2N>:GwN
(B[0BjU
)<!y_;$A
//打印回应的头信息 &a7KdGP8V
public void logResponseHead(HttpURLConnection con) x! Z|^q
{ TqzkF7;k4
for(int i=1;;i++) 9.>v ;:vL
{ T?Hs_u{
String header=con.getHeaderFieldKey(i); A5/Q:8b
if(header!=null) R5|c4v{B
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {PdyKgM
Utility.log(header+" : "+con.getHeaderField(header)); 8 \%*4L'
else 1?Wk qQ
break; Z^s&]
} cgml^k\k^
} "Bn!<h}mg
{&G0jsA
DzH1q r
public void splitterStop() "Q-TLN5(
{ 4IIe1 .{
bStop = true; abx/h#_q
} m)g:@^$
<mi*AY
P^T]Ubv"
} ):kDWc
0LeR#l:I
M qFuZg
/* 5Ta<$t
**FileAccess.java /X; [ 9&
*//文件访问(定位，写) w<*6pPy
package NetFox; {p=`"H>
import java.io.*; ^FIpkhw
[x{'NwP?
<My4)3
public class FileAccessI implements Serializable{ |@!4BA
bXmX@A$#Io
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6Q"fRXM
RandomAccessFile oSavedFile; GHaD32
long nPos; xU6)~ae`JW
U["'>&B
J!YB_6b
public FileAccessI() throws IOException 1P;J%.{
{ ~ HN
this("",0); BE>^;`K
} %{Ib
@komb IK
O*jTrZ(k
public FileAccessI(String sName,long nPos) throws IOException R2,Z`I
{ &6deds
oSavedFile = new RandomAccessFile(sName,"rw"); (qo ?e2K
this.nPos = nPos; )09>#!*
oSavedFile.seek(nPos); W2yNwB+{
} pUF$Nq>og
*62Cf[a
@-zL"%%dw'
public synchronized int write(byte[] b,int nStart,int nLen) {+Zj}3o
{ Z#uxa
int n = -1; H.o=4[
try{ ^-nL!>FYY
oSavedFile.write(b,nStart,nLen); }IJE%
n = nLen; l/xpAx
} $Iz*W]B!
catch(IOException e) y$$|_ l@
{ D*0[7:NSO
e.printStackTrace (); tEuVn5
} ?COLjk
{HO,d{{
6K7DZ96L
return n; aoUz_7
} WQiIS0BJ *
9z#z9|hj)3
tn38T%
} L$t.$[~L
]621Z1
D]=V6l=
/* L_`D
**SiteInfoBean.java x1`4hB
*/ w!_6*
package NetFox; J.(mg D
O>y*u8
!&adO,jN+=
public class SiteInfoBean { \RS0mb
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sa?s[
private String sSiteURL; //Site's URL 7}L.(Jp9
private String sFilePath; //Saved File's Path "M3S
private String sFileName; //Saved File's Name I]ZksC
private int nSplitter; //Count of Splited Downloading File XUVBD;"f!
}ijFvIHV
SuA @S
public SiteInfoBean() 1\aV4T
{//nSplitter的缺省值为5 kx%\Cz
//default value of nSplitter is 5 uquY z_2
this("","","",5); OIs!,G|
} R8>17w.
KK?R|1VK9
QL\3|'a
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) XMF#l]P
{ bg2r
sSiteURL= sURL; O[8wF86R
sFilePath = sPath; gm$<U9L\v
sFileName = sName; FwV5{-(
this.nSplitter = nSpiltter; G;e)K\[J
62o nMY
h ^Wm03w
} QsPZ dC
)0\D1IFJ
'#Q\p6G&_
public String getSSiteURL() sWq@E6,I
{ /tJ%gF
return sSiteURL; U9XOs)^
} 6u,w
?s]?2>p
l]L"Ex{
public void setSSiteURL(String value) WS+uKb^<
{ ;vUw_M{P=)
sSiteURL = value; BO>[\!=y
} 'DUYf5nF
E8.1jCL>{"
1`9'.w+r
public String getSFilePath() #;\tgUQ
{ nc?Oj B
return sFilePath; p@3 <{kLm
} eK/rsr
8Ib5
%.s"l6 W
public void setSFilePath(String value) `L"l{^cH
{ 5r^u7k
sFilePath = value; zrV~7$HL
} Zb2.o5#}
A[Vhy;xz
#Qd"d3QG
public String getSFileName() ~t^'4"K*
{ b(_PV#@$
return sFileName; +?Y(6$o
} k&o1z'<C
@qB1:==@7
_'P!>C!
public void setSFileName(String value) }#E~XlX^
{ 'Inqa;TQz
sFileName = value; ]ChN]>o
} !{4bC
@W!cC#u
#zKF/H|_R
public int getNSplitter() #}zL?s^G
{ ?N@p~ *x
return nSplitter; vU, ]UJ}
} pAdSOR2
`L {dF
0& ?/TSC
public void setNSplitter(int nCount) O\zGN/!
{ mYqRN1%
nSplitter = nCount; ZTP&*+d
} ' Y.s}Duj
} Js!V,={iX
uM9RlI5
x2H?B`5
/* j?P8&Fm<
**Utility.java JheF}/Bx
*/ [<7Vv_\Q
package NetFox; ue#Yh
U)grC8 C
N;d@)h(N!
public class Utility { '}T6e1#JV
QyX ?
oyY0!w,Y
public Utility() e{33%5
{ J2adA9R/,
(@1*-4l
rocG;$[
} zE\@x+k.
R2$;f?;:
//线程睡眠 =e$6o2!'}
public static void sleep(int nSecond) 4`#3p@-
{ E>3fk
try{ , *A',
Thread.sleep(nSecond); A9HJWKO
} -w:F8k ~
catch(Exception e) pu +"bq
{ ;n,@[v
e.printStackTrace (); $!_]mz6*
} ^?)o,djY&
} ) b vZ~t+^
HrZ\=1RB
//日志 Ll !J!{
public static void log(String sMsg) |Skk1#
{ yprf `D>
System.err.println(sMsg); d8? }69:h
} 9\]%N;;Lo
@P^8?!i+
RqIic\aD
public static void log(int sMsg) 8U07]=Bt<
{ ;O2r+n
System.err.println(sMsg); Jyx6{Oj
} nKJJ7 RL
} Dm1;mRS+
5]&vs!wH
z Lw=*
/* y#3mc#)k
**TestMethod.java M<,E[2op
*/ K>TdN+Z}=
package NetFox; 1CiK&fQ'
#KonVM(`
3+;}2x0-F
public class TestMethod { !Q`GA<ikv
r`|/qP:T[
yFT)R hN
public TestMethod() X$zlR)Re
{ ///xx/weblogic60b2_win.exe r[zxb0YA
try{ ;(Q4x"?I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ldo7}<s
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5uK:f\y)l
SiteFileFetch fileFetch = new SiteFileFetch(bean); N9D<wAK##)
fileFetch.start(); |Ebwl]X2
} Memz>uux
catch(Exception e){e.printStackTrace ();} ]k%Yz@*S
<h2WM (n
/lSz8h2
} 31LXzQvFG
:luVsQ
D L_{q6ZK
public static void main(String[] args) tm~V+t!mj
{ =N`"%T@=
new TestMethod(); }+0{opY4R
} Dx =ms^oN5
} ^0R.U+?+
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