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)); rwr>43S5<3
} _O~DJ"
for(int i=0;i<nEndPos.length-1;i++) 'VCF{0{H~
{ dC;@ Fn
nEndPos = nStartPos[i+1]; -xtj:UO
} U}(*}Ut
nEndPos[nEndPos.length-1] = nFileLength; 8)3g!3S
} g83]/s+
} x7 jE Ns )
xS]=WO*
aLTC#c%U
//启动子线程 W>036
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 09pnM|8A
for(int i=0;i<nStartPos.length;i++) G (Fi
{ WP7*Q:5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), };!S2+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), GMRw+z4
nStartPos,nEndPos,i); k8w }2Vw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PO5/j
fileSplitterFetch.start(); <m"Zk k
} lw0l86^Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IBr?6_\%"4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /qA\|'~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <)+9PV<w
nEndPos = " + nFileLength); D_@WB.eL
// fileSplitterFetch[nPos.length-1].start(); AjB-&Z
d4F3!*@(
+s.r!?49+
//等待子线程结束 b_@MoL@A!
//int count = 0; dM8`!~#&PI
//是否结束while循环 w$4fS
boolean breakWhile = false; lpLjfHr
.p&4]6
uG@Nubdwuy
while(!bStop) m[,! orq
{ ,Hn{nVU1R=
write_nPos(); OF'y]W&
Utility.sleep(500); $NzD&b$7
breakWhile = true; {j.5!Nj]B
<[Ae0UK
}N!I|<"/
for(int i=0;i<nStartPos.length;i++) lAz.I
{ i/`N~r
if(!fileSplitterFetch.bDownOver) ntE;*FyH
{ Q)S0z2
breakWhile = false; $+qJ#0OE$
break; gH5E+J_$
} EOWLGleD1
} pme5frM|
if(breakWhile) +DFG762
break; k\X1`D}R
sui3(wb
q"4{GCavN
//count++; OD 09XO
//if(count>4) < I[ Vv'x
// siteStop(); p=_K P9
} M \rW
Kf#9-.}?
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System.err.println("文件下载结束！"); <z+5+h|^
} ).e_iE[&
catch(Exception e){e.printStackTrace ();} \?A 7{IY
} XOK.E&eilj
:4|ubu
Lgl%fO/<t
//获得文件长度 e>\[OwF-x
public long getFileSize() uuW._$.A>
{ ," ~ew ,
int nFileLength = -1; c.y8x
try{ WrBiAh,
URL url = new URL(siteInfoBean.getSSiteURL()); ;@xSJqT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T7_i:HU%
httpConnection.setRequestProperty("User-Agent","NetFox"); udYk 6
/f2HZfj
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int responseCode=httpConnection.getResponseCode(); H;5FsKIF
if(responseCode>=400) bC{1LY0
{ dHjJLs_
processErrorCode(responseCode); WBdC}S }3t
return -2; //-2 represent access is error k!-(Qfz
} uBp"YX9rx
j}~3m$
Ao>] ~r0
String sHeader; KLi&TmIB
CPGiKE
G*.}EoA
for(int i=1;;i++) #1c%3KaZI
{ HAJK%zLc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); CYD&#+o
//Utility.log(in.readLine()); 8wJfGY
sHeader=httpConnection.getHeaderFieldKey(i); w+c%Y\:
if(sHeader!=null) ]Q-*xho
{ CtiTXDc_
if(sHeader.equals("Content-Length")) $<&N#
{ <2Q+? L{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1#BMc%
break; ;#a^M*e
} zyb>PEd.
} GSck^o2{
else v%8.o%G
break; Bg.~#H
} &|cg`m
} Hg<d%7.
catch(IOException e){e.printStackTrace ();} VnqgN
catch(Exception e){e.printStackTrace ();} _Ec9g^I10
4 XSEN]F
>6xZF'4
Utility.log(nFileLength); >drG,v0qh
}',/~T6
! *Snx
return nFileLength; vV5dW
} #w_cos[I
7mG/f
1yHlBeEC
//保存下载信息（文件指针位置） zF'LbQz0[
private void write_nPos() 53>y<
{ RE~9L5i5
try{ QYS 1.k
output = new DataOutputStream(new FileOutputStream(tmpFile)); !Eqp,"ts7
output.writeInt(nStartPos.length); Npr<{}ZE
for(int i=0;i<nStartPos.length;i++) [m*E[0Hu
{ PM(M c]6
// output.writeLong(nPos); AbqeZn
output.writeLong(fileSplitterFetch.nStartPos); pgp@Zw)r)k
output.writeLong(fileSplitterFetch.nEndPos); %1\MW+
} "W"2Y(
output.close(); \ytF@"7
} F\K&$5J{p
catch(IOException e){e.printStackTrace ();} t@_MWF
catch(Exception e){e.printStackTrace ();} W##~gqZ/
} U3oMY{{EJ
ff{L=uj
T(@J]Y-
//读取保存的下载信息（文件指针位置） w# iezo. 0
private void read_nPos() J>o%6D
{ "A4.2
try{ [5"F=tT7WP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `l%)0)T
int nCount = input.readInt(); m|/q o
nStartPos = new long[nCount]; c] '-:=
nEndPos = new long[nCount]; `]T#uP<u
for(int i=0;i<nStartPos.length;i++) zyHHz\{
{ fN|'aq*Pd
nStartPos = input.readLong(); F4b$
nEndPos = input.readLong(); (4GDh%
} 6g6BE^o\
input.close(); hxT{!g
} Hv3<gyD
catch(IOException e){e.printStackTrace ();} ;ZasK0
catch(Exception e){e.printStackTrace ();} y;$ !J
} j0X Jf<
u#Z#NP ~F0
Z<Rhn
private void processErrorCode(int nErrorCode) u`ezQvrcy
{ o*r 2T48
System.err.println("Error Code : " + nErrorCode); "/#=8_f
} .)Wqo7/Gx
.%x1%TN
W Z_yaG$U
//停止文件下载 &{gD(QG
public void siteStop() fzk^QrB
{ Zf,9 k".'C
bStop = true; 3$~oQC
for(int i=0;i<nStartPos.length;i++) 2jT2~D.U1
fileSplitterFetch.splitterStop(); grs~<n|o\
IEP^u `}
zP`&X:8
} R?Dc*,
} G+SMH`h
//负责部分文件的抓取 ~BbF:DS
**FileSplitterFetch.java dEvjB"x
*/ -^f>=xa4J
package NetFox; !k}]`z^d
GKg&lM!O$
Y9w^F_relL
import java.io.*; |ctcY*+
import java.net.*; zF7*T?3b"
k^i\<@v
YqEB%Y~N+
public class FileSplitterFetch extends Thread { R2Y.s^
-~rZ| W~v
5 A2u|UU
String sURL; //File URL @ )2<$d
long nStartPos; //File Snippet Start Position OMz_xm.UPi
long nEndPos; //File Snippet End Position oNFvRb2Rd
int nThreadID; //Thread's ID )J>-;EYb8
boolean bDownOver = false; //Downing is over {Y6;/".DM
boolean bStop = false; //Stop identical aS3Fvk0R{h
FileAccessI fileAccessI = null; //File Access interface !\hUjM+(}
cq0#~20
vxt<}h5J/!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +#LD@)G
{ Q|] 9
this.sURL = sURL; mh:eUFe
this.nStartPos = nStart; <?E~Qc t
this.nEndPos = nEnd; Oe_*(q&
nThreadID = id; R\MFh!6sn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gc[BP>tl\
} =}xH6^It
py':UQS*q
qHf8z;lc
public void run() y7@q]~%
{ of<(4<T
while(nStartPos < nEndPos && !bStop) %-Oo92tP
{ p OO4fc
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sqE? U*8.-
try{ ]N4?*S*jd)
URL url = new URL(sURL); JIh:IR(ta
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RbN# dI'
httpConnection.setRequestProperty("User-Agent","NetFox"); 9J(jbJ7p
String sProperty = "bytes="+nStartPos+"-"; Pq<]`9/w^w
httpConnection.setRequestProperty("RANGE",sProperty); )ePQN~#K}
Utility.log(sProperty); 7|Bg--G1
U:+wt}-T"
NU/:jr.W#
InputStream input = httpConnection.getInputStream(); %kXg|9Bx!
//logResponseHead(httpConnection); uk<JV*R=
T~G~M/
tEl_a~s*3?
byte[] b = new byte[1024]; (;T g1$
int nRead; &Z%|H>+;T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Uf`~0=w
{ Z%9_vpWc
nStartPos += fileAccessI.write(b,0,nRead); ]R%+
//if(nThreadID == 1) fKkH [
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y=qiGi[Nc
} -d8U Hc
2r*Yd(e
fb;y*-?#
Utility.log("Thread " + nThreadID + " is over!"); K)_DaTmi)
bDownOver = true; j3_vh<U\
//nPos = fileAccessI.write (b,0,nRead); /{sFrEMP\
} WcZck{ehd
catch(Exception e){e.printStackTrace ();} o>?#$~XNv
} k=``Avp?
} 01&J7A2
)2dTgvy
>[&Zs3>
//打印回应的头信息 0$1-5XY9
public void logResponseHead(HttpURLConnection con) WJs2d73Qp
{ ` Clh;
for(int i=1;;i++) 5fuB((fd(
{ 79G& 0 P\
String header=con.getHeaderFieldKey(i); 6ntduXeNVh
if(header!=null) ]zUvs6ksLG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); TBr@F|RXiO
Utility.log(header+" : "+con.getHeaderField(header)); d"~-D;
else {~a+dEz
break; 4O1[D?)`x
} E(/M?>t-
} 9TZ4ffXV*
@q<F_'7is
m|%ly
public void splitterStop() l/:23\
{ Ow f:Kife
bStop = true; $5v:z
} rc()Eo50
IuN:*P
0.kQqy~5
} _YPu
KoF_G[m
HCOE'24I
/* Bq*aP*jv
**FileAccess.java ,o68xfdZVW
*//文件访问(定位，写) [_w;=l0 ;
package NetFox; jTE~^
import java.io.*; vd]75
p8_ CY[U
r]lPXj(`
public class FileAccessI implements Serializable{ 4!)=!sL;
2oFbS%OV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o5`LLVif5y
RandomAccessFile oSavedFile; = k7}[!T
long nPos; EI!e0V1!
G}ccf%
+u|p<z
public FileAccessI() throws IOException SZ3UR
{ z(JDLd
this("",0); /\e&nYz
} zilM+BZ8
G.y~*5?#
1?hx/02
public FileAccessI(String sName,long nPos) throws IOException %9Y3jB",2
{ iciw 54;4
oSavedFile = new RandomAccessFile(sName,"rw"); ae-hQF&
this.nPos = nPos; Ks_B%d
oSavedFile.seek(nPos); qG?svt
} #[ZNiaWT
NpN-''B\
s?pd&_kOv3
public synchronized int write(byte[] b,int nStart,int nLen) KV {J>J1
{ l0GsY.~,
int n = -1; j]5mzz~
try{ R[T94U
oSavedFile.write(b,nStart,nLen); d&apu{
n = nLen; Z@d(0 z
} B>XfsZS
catch(IOException e) Ir\f_>7
{ u/S{^2`b
e.printStackTrace (); uqFYa bU
} +q-/~G'
TeXt'G=M
/lqVMlz\77
return n; n,vs(ZL:
} ?X5Y8n]y\h
}=T=Z#OgH
`iT{H]po
} v[J"/:]
Yv ZcG3@c3
C]'ru
/* 8\])p sb9
**SiteInfoBean.java &8R!`uh1
*/ :,[=g$CT:
package NetFox; d]!`II
5?M d
io^L[
public class SiteInfoBean { 'j27.Ry.
k3S
&w7Ev21
private String sSiteURL; //Site's URL 6X`i*T$.
private String sFilePath; //Saved File's Path |jT^[q(z
private String sFileName; //Saved File's Name XjINRC8^4
private int nSplitter; //Count of Splited Downloading File 8AgKK=C=
-Mx\W|YK
vWpoaz/w
public SiteInfoBean() BfOQ/k))
{//nSplitter的缺省值为5 PTZ/jg@71
//default value of nSplitter is 5 Z?"f#
this("","","",5); >.4mAO
} \!Cc[n(f#
!eE;MaS>
BK;Gh0mp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {.mPe|
{ i0/RvrLc
sSiteURL= sURL; Pua|Z x
sFilePath = sPath; x_VD9
sFileName = sName; yNc"E
this.nSplitter = nSpiltter; 14Y<-OO: k
'2X6>6`w
:Y)jf
} %3;vDB*L$
5%)<e-
mMSQW6~j
public String getSSiteURL() YggeKN
{ &'KJh+jJ
return sSiteURL; 4M,Q{G|e
} Z(c3GmY
|0N6]%r
MFzJ 8^.1R
public void setSSiteURL(String value) b;k3B7<
{ R.'-jvO
sSiteURL = value; h}$g}f%$+
} lNRGlTD%
SR8)4:aKW
Q!*}^W
public String getSFilePath() 56`Tna,t
{ rK@XC +`S
return sFilePath; Vz @2_k
} vmsrypm
R!Lh~~@{(
c+A$ [
public void setSFilePath(String value) 4-voR5Fd
{ }"x#uG
sFilePath = value; s:ZYiZ-
} k3yA*Ec
=9yh<'583
T j(MIFi|5
public String getSFileName() Z`]r)z%f
{ xP+`scv*m#
return sFileName; qEJ#ce]G
} <reALC
-g\;B
:}*
public void setSFileName(String value) Qo$j'|lD
{ dn1Fwy.
sFileName = value; wSd|-e
} A29R5
kJ[r.)HU
n4sO#p)'
public int getNSplitter() 6Q*Zy[=
{ D8 BmC
return nSplitter; r7^oqEp@B
} s~'"&0Gz
67b w[#v
*hvC0U@3
public void setNSplitter(int nCount) (|9t+KP
{ {|{;:_.>
nSplitter = nCount; 'zhv#&O
} l9t|@9
} v|Y ut~
nghpWODq
cNl NJ
/* L+.&e4f'oj
**Utility.java E< Y!BT[X
*/ q>rDxmP<
package NetFox; ^V7'S<
c:I %jm
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public class Utility { rt0_[i
l=PZlH y1G
0PD=/fh[
public Utility() Ji)Ys ebV
{ ).3riR
J!\oH%FJp
e);`hNLih
} Z^!% b
Fs(FI\^
//线程睡眠 0fzHEL
public static void sleep(int nSecond) y|/[;
{ aqEmF
try{ {/}%[cY=
Thread.sleep(nSecond); ey@ccc*sZ9
} 6,cJ3~!48
catch(Exception e) cDIZkni=
{ %#x l+^
e.printStackTrace (); U8zCV*ag
} ZM16 ~k
} $1 t IC_
Vbv)C3ezD
//日志 i_(6}Y&
public static void log(String sMsg) |=js!R|
{ Ozg,6&3ji
System.err.println(sMsg); xn=#4:f
} %uw7sGz\
&WNIL13DK
fE"-W{M
public static void log(int sMsg) l;d4Le
{ C#LTF-$])
System.err.println(sMsg); R} X"di
} k8c(|/7d
} jwpahy;\WL
H<") )EJI
5=#2@qp
/* $5:I~-mx
**TestMethod.java FsLd&$?T&
*/ (q@%eor&}
package NetFox; hg2Ywzfm-
[}HS[($
X-*LA*xbN
public class TestMethod { fjCFJ_
d$^@$E2f
:%_h'9Qq
public TestMethod() Vi`P &uPF
{ ///xx/weblogic60b2_win.exe KM"BHaSkF
try{ jO-T1P']Y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,rV;T";r
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); I? ="Er[g}
SiteFileFetch fileFetch = new SiteFileFetch(bean); U+R9bn
fileFetch.start(); vnWt8?)]^
} (8baa.ge
catch(Exception e){e.printStackTrace ();} #(QS5J&Qq
+Sc2'z>R
NL,6<ZOon,
} ++n_$Qug
%l?*w~x
$*`E;}S0
public static void main(String[] args) x_t$*
{ ^WF_IH&
new TestMethod(); aLl=L_
} Q zg?#|
} d_!}9
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