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"h,(^
} ,$7LMTVDrE
for(int i=0;i<nEndPos.length-1;i++) 2u/(Q>#
{ DJT)7l{
nEndPos = nStartPos[i+1]; ,]]*}4[r
} U3Z-1G~*r
nEndPos[nEndPos.length-1] = nFileLength; PTqia!
} W|y;Kxy
} k+vfZ9bD(J
Rd|8=`)
(.VS&Kv#U
//启动子线程 P,F eF'J^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wm_rU]
for(int i=0;i<nStartPos.length;i++) mCG&=Fx
{ *>1^q9M
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k%Vprc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _x|.\j
nStartPos,nEndPos,i); (z?j{J
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n?;rWq"
fileSplitterFetch.start(); To5hVL<Ex"
} HIx%c5^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PB?2{Cj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =I@I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0!7p5
nEndPos = " + nFileLength); Z#bO}!
// fileSplitterFetch[nPos.length-1].start(); S!+>{JyQ
:7mHPe}(
/ *PHX@
//等待子线程结束 w6WPfy(/2
//int count = 0; ,?k1if(0[
//是否结束while循环 .T3 m%n
boolean breakWhile = false; a@d 15CN
o. ;Vrc
t(9q6x3|e
while(!bStop) Y#tur`N
{ Q2uV/M1?
write_nPos(); I.GoY[u_%
Utility.sleep(500); f'H|K+bO
breakWhile = true; !!H"B('m
nSC2wTH!1
@NqwJ.%g
for(int i=0;i<nStartPos.length;i++) GNe^~
{ "Y=`w,~~
if(!fileSplitterFetch.bDownOver) \Z&Nd;o
{ qc5[e
breakWhile = false; H(rD*R[
break; ^B%=P
} !hhL",
} nS*Y+Q^9a
if(breakWhile) m<#12#D
break; .\glNH1d
V?1 $H
qS FtQ4
//count++; cgSN:$p(R
//if(count>4) oSC'b%
// siteStop(); $[n:IDa*@1
} mpMAhm:
ABX%oZ7[|o
q1( [mHZ
System.err.println("文件下载结束！"); dkZe.pv$j
} g}xL7bTlI>
catch(Exception e){e.printStackTrace ();} k[;)/LfhS
} Y}N\|*ye-
oDz|%N2s|
P*OG`%y
//获得文件长度 7MLLx#U
public long getFileSize() y]m: {
{ 7RL J
int nFileLength = -1; `KFEzv
try{ nQjpJ /=
URL url = new URL(siteInfoBean.getSSiteURL()); -}|L<~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )hXTgUZa
httpConnection.setRequestProperty("User-Agent","NetFox"); +*]$PVAFA
<$0is:]
pg4W?N`
int responseCode=httpConnection.getResponseCode(); &uK(. @
if(responseCode>=400) alaL/p{O
{ ~v.mbh
processErrorCode(responseCode); K8;SE!
return -2; //-2 represent access is error ERpAV-Zf
} .ybmJU*Hg
[-])$~WfW
A'DFY {
String sHeader; hul,Yd) Z
CO='[1"_5
4]h/t&ppq
for(int i=1;;i++) olE(#}7V
{ dFy$w=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g X!>ef
//Utility.log(in.readLine()); )!2@v@SQ
sHeader=httpConnection.getHeaderFieldKey(i); nF<K84
if(sHeader!=null) _x,X0ncv]@
{ f+cb83}n]
if(sHeader.equals("Content-Length")) 5H0qMt P
{ IzpE|8l
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~)U50.CH
break; >1j#XA8
} lYG`)#T
} 4X+xh|R:U
else <fvu) f
break; I%YwG3uR
} 5n3yc7NPP
} ys9:";X;}
catch(IOException e){e.printStackTrace ();} r1L@p[>
catch(Exception e){e.printStackTrace ();} ;g0Q_F@;p
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hIe.Mv-I)
Utility.log(nFileLength); YEu+kBlcQ
s2O()u-
QLY;@-jF$
return nFileLength; COh#/-`\1
} x%viCkq
jY=y<R_oK
YSP\+ZZ
//保存下载信息（文件指针位置） ZmsYRk~@-
private void write_nPos() b Hr^_ogN
{ Fv^zSoi2
try{ $${I[2R)
output = new DataOutputStream(new FileOutputStream(tmpFile)); w}3N!jNDv
output.writeInt(nStartPos.length); 3``JrkPI
for(int i=0;i<nStartPos.length;i++) |+ F ~zIu'
{ t2dsYU/
// output.writeLong(nPos); w-K A~
output.writeLong(fileSplitterFetch.nStartPos); 1-y8Hy_a2
output.writeLong(fileSplitterFetch.nEndPos); dA)T>
} rfwJLl/
output.close(); ~B;}jI]d[
} ,Cr%2Wg-
catch(IOException e){e.printStackTrace ();} `etw[#~N
catch(Exception e){e.printStackTrace ();} 0AO^d[v
} ~+\=X`y
"'v+*H 3
+f/ I>9G
//读取保存的下载信息（文件指针位置） EH844k8 p
private void read_nPos() MLd;UHU
{ #}^waYAk)
try{ :!aLa}`@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v`|]57?A
int nCount = input.readInt(); g{N}]_%Uh
nStartPos = new long[nCount]; BM!ZdoKrKt
nEndPos = new long[nCount]; -}6ew@GE
for(int i=0;i<nStartPos.length;i++) x1 |/
{ @aS)=|Ls\
nStartPos = input.readLong(); l[E^nh>
nEndPos = input.readLong(); yQhO-jT
} };'@'
input.close(); dj0%?g>
} T1Py6Q,-
catch(IOException e){e.printStackTrace ();} {"]!zL
catch(Exception e){e.printStackTrace ();} ~R|9|k
} FAM{p=t]HT
-E}X`?WhD
dXTD8 )&
private void processErrorCode(int nErrorCode) #da{3>z:
{ V*n$$-5 1-
System.err.println("Error Code : " + nErrorCode); 63E6nW M
} Ek<Qz5)
h3`}{ w
Z#.d7B"
//停止文件下载 Ck/44Wfej
public void siteStop() WOn53|GQK
{ 'HWl_M
bStop = true; 6k hBT'n
for(int i=0;i<nStartPos.length;i++) 3wfcGQn|sD
fileSplitterFetch.splitterStop(); EV( F!&
|:C0_`M9
~ky;[
} |3~m8v2-
} ]njNSn
//负责部分文件的抓取 Pg}QRCB@
**FileSplitterFetch.java v*V(hMy
*/ cvsH-uAp
package NetFox; eKOEOm+
Fv]6an.
l73% y
import java.io.*; 8y27O
import java.net.*; Q\4tzb]
kl]V_ 7[
%?[gBf[y
public class FileSplitterFetch extends Thread { 9]v,3'QI
CT'4.
;B@#,6t/
String sURL; //File URL S${%T$>
long nStartPos; //File Snippet Start Position 8gavcsVE[
long nEndPos; //File Snippet End Position &pY'
int nThreadID; //Thread's ID zg ,=A?
boolean bDownOver = false; //Downing is over t{c:<nN
boolean bStop = false; //Stop identical +.~K=.O)
FileAccessI fileAccessI = null; //File Access interface x\'3UKQP+^
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(kR NqfX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |mKohV qr
{ n{N0S^h
this.sURL = sURL; =6U5^+|d
this.nStartPos = nStart; \lG)J0
this.nEndPos = nEnd; dm}1"BU<
nThreadID = id; m]V#fRC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sl-wNIQ
} ,Vq$>T@z
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/)kJ iV
public void run() f_)#
{ }vh <x6
while(nStartPos < nEndPos && !bStop) Ub\^3f
{ (-$5YKm
y7/4u-_c
&wlD`0v
try{ :4AIYk=q
URL url = new URL(sURL); z00X ?F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FdE?uw
httpConnection.setRequestProperty("User-Agent","NetFox"); eGT&&Y
String sProperty = "bytes="+nStartPos+"-"; NxF:s,a6
httpConnection.setRequestProperty("RANGE",sProperty); Z-lhJ<0/Pa
Utility.log(sProperty); AM=> P7
9ye!kYF,
j5DCc,s
InputStream input = httpConnection.getInputStream(); :xHKbWz6j
//logResponseHead(httpConnection); T;3qE1c
4!Radl3`
Lxv;[2XsW)
byte[] b = new byte[1024]; 9n is8
int nRead; 7vXP|8j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LpY{<:y
{ 8Tg1 >q<
nStartPos += fileAccessI.write(b,0,nRead); AmC9qk8Q
//if(nThreadID == 1) `Kg!aN
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XY{N"S8
} {96MfhkeBv
Ce-= -
D} B?~Lls
Utility.log("Thread " + nThreadID + " is over!"); OIj.K@Kr
bDownOver = true; UF^[?M =
//nPos = fileAccessI.write (b,0,nRead); Y=|p}>.}
} 7[P-;8)tq
catch(Exception e){e.printStackTrace ();} "Y^j=?1k
} S`YT"|~
} r+m.!+
HI{q#
'k]~Q{K$
//打印回应的头信息 }F0<8L6%
public void logResponseHead(HttpURLConnection con) kJl^,q
{ u=Ik&^v Wq
for(int i=1;;i++) s<"|'~<n
{ 'm`}XGUBS
String header=con.getHeaderFieldKey(i); UapU:>!"`
if(header!=null) 5?HwM[`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B-_b.4ND)
Utility.log(header+" : "+con.getHeaderField(header)); @gbW:
else l'q%bi=f
break; OQfFS+6
} .]h/M,xg
} G=[<KtWa
f6K.F
,ja!OZ0$
public void splitterStop() pt"9zkPj
{ niCK(&z
bStop = true; a(6h`GHo
} `1P|<VbZ
al}J^MJ
s&pnB
} vE^tdzAG
@Q,Q"c2
N,K/Ya)1
/* s!?uLSEdb
**FileAccess.java mrRid}2
*//文件访问(定位，写) 8Yk*$RR9
package NetFox; -t S\
import java.io.*; d/yF}%0QI
4@{?4k-cq
OWwqCPz.
public class FileAccessI implements Serializable{ +'c+X^_
W9w*=W )Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FfM^2`xP
RandomAccessFile oSavedFile; sw}O g`U
long nPos; (o IGp
S=-$:65
8u~
public FileAccessI() throws IOException 7Q&-ObW
{ Kw`CN
this("",0); `K5*Fjx
} xrvM}Il
m=l'9j"D
DNq(\@x[!
public FileAccessI(String sName,long nPos) throws IOException pml33^*<U
{ >-N(o2j3
oSavedFile = new RandomAccessFile(sName,"rw"); sq`Xz8u
this.nPos = nPos; pAatv;Ex
oSavedFile.seek(nPos); "."(<c/3
} <9ucpV
LE<J<~2Z
O_1[KiZ
public synchronized int write(byte[] b,int nStart,int nLen) 7?R600OA
{ la+Cra&xL
int n = -1; o:Kw<z,$H
try{ A811VL^
oSavedFile.write(b,nStart,nLen); *p $0(bz
n = nLen; 4{kH;~ z$
} `5@F'tKQ
catch(IOException e) vi,hWz8WB
{ ]O@$}B];)
e.printStackTrace (); ,;)ZF
} 9njl,Q:
2c9?,Le/;
[^5\Ww
return n; 4%(Ji
} y?$DDD
V ;T :Q%
N^Re
} P49\A^5S!
(`tRJWbdz
c3vb~l)
/* *%j$i_
**SiteInfoBean.java #.Rn6|V/4
*/ 5~*)3z^V
package NetFox; y~SVD@
t[^$F,
8H!QekQZ]\
public class SiteInfoBean { xA] L0h]
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)g0fN+Mb
private String sSiteURL; //Site's URL AU{"G
private String sFilePath; //Saved File's Path oaoTd$/5
private String sFileName; //Saved File's Name )pnyVTKt
private int nSplitter; //Count of Splited Downloading File tdy2ZPVtTV
+a1x;
-3I3 X
public SiteInfoBean() M([#Py9h
{//nSplitter的缺省值为5 MY&Jdmga
//default value of nSplitter is 5 Uzu6>yT
this("","","",5); "LMj,qZ1!
} D&@]
%,$n^{v
[|}IS@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yIMqQSt79z
{ *H>rvE.K?
sSiteURL= sURL; \8`?ir q"
sFilePath = sPath; kB\{1;
sFileName = sName; @-N` W9
this.nSplitter = nSpiltter; / HTY>b
N;7/C
wj|Zn+{"nF
} 6@S6E(^
1>!LK_
sp9gz~Kq
public String getSSiteURL() .])prp8
{ }aCa2%
return sSiteURL; O] _4pP
} QrZ#<{,J5
EE/mxN(<
!3ggQG!e
public void setSSiteURL(String value) LF<&gC
{ k9|5TLXq?
sSiteURL = value; my=f}%k=
} Yo-}uTkw
DSGcxM+
2_o#Gx'
public String getSFilePath() Bf_$BCyGW
{ rr<E#w
return sFilePath; <=uYfi3,
} v*;d
V7ph^^sC}
ITu19WG
public void setSFilePath(String value) &hCbXs=
{ M>Q]{/V7T
sFilePath = value; "L~(%Nx3
} /@os*c|je
_KT!OYH
H'+7z-%G
public String getSFileName() 98m|&7
{ S63Zk0(25
return sFileName; ^5mc$~1`
} L'e_?`!:
N<EVs.7
?RRO
public void setSFileName(String value) n|`3d~9$&
{ \-<BUG]=
sFileName = value; NnZW@ln"|
} ^0VL](bD>
_|HhT^\P
{]vD@)k
public int getNSplitter() '\Xkvi
{ voWH.[n^_
return nSplitter; 8hRcB[F~S
} O5\r%&$xd
>rG>Bz^Pu
`-NK:;^
public void setNSplitter(int nCount) *zfgO pK
{ :_{8amO
nSplitter = nCount; d@%"B($nR
} V0ze7tSG[f
} ,'#TdLe
)U^=`* 7
M .#}
/* W{p}N
**Utility.java 7Z-j'pq
*/ _vQ52H,
package NetFox; g40Hj Y
L"_XWno
1/_g36\l$
public class Utility { jnH\}IB
{@Wv@H+4
m0HK1'
public Utility() _0/unJl`
{ Lx"GBEkt7
X-pbSq~5
"CJVtO
} Z:4/lx7Bq
nF3}wCe)
//线程睡眠 sEhvx+(
public static void sleep(int nSecond) ?HEqv$n
{ Y\xEPh
try{ ^BsT>VSH6
Thread.sleep(nSecond); 1$E(8"l
} nep#L>LP$x
catch(Exception e) (f/(q-7VWt
{ "k zKQ~
e.printStackTrace (); 3o.x<G(
} gF6> /
} ^z,3#gK
0cG'37[
//日志 ]ua3I}_B6v
public static void log(String sMsg) l{By]S
{ F/Goq`
System.err.println(sMsg); LIg1U
} .#EU@Hc
72HA.!ry
E^8|xT'h6
public static void log(int sMsg) *PmZqe
{ :X>Wd+lY:_
System.err.println(sMsg); F)3+IuY
} tBo\R?YRs
} y^2#;0W
E@}F^0c
*V>?m6y/
/* ?kjQ_K
**TestMethod.java !gh8 Qs
*/ /9vi
package NetFox; ]#0 (
zJQh~)
2mLZ4r>WE
public class TestMethod { YQ0#j'}/
N8A)lYT]_u
Nt>^2Mv
public TestMethod() *s6x
{ ///xx/weblogic60b2_win.exe vCa8`m
try{ {}$9 70y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }[0nTd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Okq,p=D6
SiteFileFetch fileFetch = new SiteFileFetch(bean); mK:gj&N7X|
fileFetch.start(); @SfQbM##%
} Xv1vq -cM
catch(Exception e){e.printStackTrace ();} .Fb#j+Lq
'-wmY?ZFxy
b]u$!W
} 91OxUVd
@3`5(xwzm
b{0a/&&1O
public static void main(String[] args) c4z&HQd
{ !73y(Y%TE
new TestMethod(); 9r%fBiSk
} 161P%sGx2
} uq5?t
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