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)); Ok+zUA[Wu
} G"=tQ$ZU
for(int i=0;i<nEndPos.length-1;i++) fa#]G^f
{ }*~EA=YN;
nEndPos = nStartPos[i+1]; W%f:+s}cI
} fn zj@_{|
nEndPos[nEndPos.length-1] = nFileLength; Rla4XN=mf
} .F0V
} /vl]Oa&U
sD$ \!7:b
~ySmN}3~'
//启动子线程 EdA_Hf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "3{xa;c
for(int i=0;i<nStartPos.length;i++) <R7*00
{ Sq&*K9:z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U&PAs e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ru Q\H0pr
nStartPos,nEndPos,i); >wjWX{&?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^CTgo,uf6H
fileSplitterFetch.start(); n37C"qJ/i
} :4h4vp<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z&=K+P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 36JVnW;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", . ({aPtSt!
nEndPos = " + nFileLength); lnW/T--
// fileSplitterFetch[nPos.length-1].start(); #lQbMuR
Tk9*@kqv
=1lKcA[z
//等待子线程结束 )1O *~%
//int count = 0; !o*BRR*
//是否结束while循环 a J[VX)"J
boolean breakWhile = false; 3O<<XXar
geWis(#J
YL&$cT]1
while(!bStop) bvn?wK
{ ;u,%an<(
write_nPos(); mwCNfwb:
Utility.sleep(500); 'g#Ml`cm
breakWhile = true; +Bv{A3E9
&6,GX7]Fo
kjN9(&D
for(int i=0;i<nStartPos.length;i++) ExI?UGT
{ TclZdk]%T
if(!fileSplitterFetch.bDownOver) 7*OO k"9
{ nTY`1w.;
breakWhile = false; q#I/N$F
break; 9M~EH?>+[
} 1[J&^@t[h6
} )rz4IfE
if(breakWhile) Pf6rr9
break; Xgd!i}6Q
uwQ{y>SG
O~9 %!LAu
//count++; *FR Eh@R
//if(count>4) I o7pp(
// siteStop(); <|Bh;;
} oj$D3
,y,NVF
s}`ydwSg8
System.err.println("文件下载结束！"); '\l(.N
} 9Q^>.^~^
catch(Exception e){e.printStackTrace ();} '%V ;oJ"
} s41<e"
!V Zl<|
'7 6}6G%
//获得文件长度 >6=yxCJ
public long getFileSize() _,NL;66=[
{ h;^h[q1'
int nFileLength = -1; 2z:4\Y5
try{ d'kQE_y2.
URL url = new URL(siteInfoBean.getSSiteURL()); 7}%3Aw6]S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X;v/$=-mz
httpConnection.setRequestProperty("User-Agent","NetFox"); aIRCz=N
=YB3^Z
C z4"[C`;
int responseCode=httpConnection.getResponseCode(); X/];*='Q
if(responseCode>=400) +T [0r
{ 6t*pV [
processErrorCode(responseCode); k^p|H:
return -2; //-2 represent access is error x7t<F4
} e~W35Y>A
`U#*O+S-^
e8a_)TU?
String sHeader; \Z ] <L
p` B48TW
%^p1ax
for(int i=1;;i++) 6QLWF@
{ ;B^G<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Um4 }`
//Utility.log(in.readLine()); =~?2i)-mC
sHeader=httpConnection.getHeaderFieldKey(i); z(:0@5
if(sHeader!=null) f%an<>j^w
{ AGx]srl
if(sHeader.equals("Content-Length")) .*r?zDV
{ M9_ y>N[0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tU}CRh
break; 5MQD:K2
} 7;5?2)+=6
} w_ kHy_)
else {e/12q
break; .YYiUA-i9n
} R."<he ;
} 9Y&n$svB
catch(IOException e){e.printStackTrace ();} =IkQ;L&
catch(Exception e){e.printStackTrace ();} ua0`&,a3I
f#ID:Ap3
Tt`|26/
Utility.log(nFileLength); 1U;je,)
7Wmk"gp
?#-"YO7
return nFileLength; 9jDV]!N4
} `l9Pk\X[
rqxoqcZ
(Q o
//保存下载信息（文件指针位置） YjdCCju
private void write_nPos() I+kGEHO}
{ O"<D0xzF?
try{ )TP1i
output = new DataOutputStream(new FileOutputStream(tmpFile)); ``nuw7\C:
output.writeInt(nStartPos.length); 3Nd&*QSV
for(int i=0;i<nStartPos.length;i++) g;i>nzf
{ k:Da+w_'1
// output.writeLong(nPos); 5n"b$hMF
output.writeLong(fileSplitterFetch.nStartPos); &{!FE`ZC_
output.writeLong(fileSplitterFetch.nEndPos); >2x[ub%$L
} btkD<1{g
output.close(); = 7d{lK
} KS!mzq-
catch(IOException e){e.printStackTrace ();} 'H`aQt+
catch(Exception e){e.printStackTrace ();} -M2c8P:.b
} z4!TK ps
&W`."
H5'/i;
//读取保存的下载信息（文件指针位置） {u{n b3/jl
private void read_nPos() OBqaf )W
{ zlco?Rt
try{ +)k%jIi!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KC9_H>
int nCount = input.readInt(); 8iaP(*J
nStartPos = new long[nCount]; X,y0J
nEndPos = new long[nCount]; wa-#C,R\_#
for(int i=0;i<nStartPos.length;i++) HJ?p,V q5_
{ tGDsZ;3Yr
nStartPos = input.readLong(); )ZC0/>R
nEndPos = input.readLong(); FpN>T
} Xb6X'rY
input.close(); `n7*6l<k~4
} ))- B`vi
catch(IOException e){e.printStackTrace ();} #\3(rzQVO
catch(Exception e){e.printStackTrace ();} }iZO0C
} LlOUK2tZ
luXcr H+w
mX66}s}#
private void processErrorCode(int nErrorCode) ,j\1UAa
{ = i9|lU"Va
System.err.println("Error Code : " + nErrorCode); P7np -I*
} CzDJbvv]
*{[jO&&J
m%au* 0p
//停止文件下载 M9so3L<N0
public void siteStop() 4+46z|
{ R@zl?>+
bStop = true; 21ng94mC
for(int i=0;i<nStartPos.length;i++) #fdQ\)#q>
fileSplitterFetch.splitterStop(); PCKgdh},
|hGi8
[HO=ii]Wb
} Q|T9tc->
} 0P)"_x_
//负责部分文件的抓取 l@C39VP
**FileSplitterFetch.java X'[93 C|K
*/ ]1YyP
package NetFox; @px4[
o&-c5X4
?mM6[\DFoT
import java.io.*; XQW9/AzNf
import java.net.*; /D@(o`a
oY;=$8y<q
vfnVN@ 5
public class FileSplitterFetch extends Thread { (Qf"|3R4
o]gS=iLp
(zv)cw%
String sURL; //File URL qC|$0
long nStartPos; //File Snippet Start Position *.g@6IkAQ
long nEndPos; //File Snippet End Position Pgdv)i3
int nThreadID; //Thread's ID P/9iB/
boolean bDownOver = false; //Downing is over v7Q=
boolean bStop = false; //Stop identical A08b=S
FileAccessI fileAccessI = null; //File Access interface ??MF8uv
RlW7l1h&
T][r'jWQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException OsSGVk #Qh
{ =A yDVWpE
this.sURL = sURL; %BV2 q
this.nStartPos = nStart; a d,0*(</
this.nEndPos = nEnd; )U$]J*LI
nThreadID = id; =5zx]N1r
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d|~A>YZ
} OvFWX%uY
? FlV<nE"J
utJz e
public void run() ww0m1FzX
{ xQKD1#y
while(nStartPos < nEndPos && !bStop) ohy?l
{ Wd0$t
{1jywb }
$AI0&#NM
try{ ^KK9T5H
URL url = new URL(sURL); G0u3*.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GNv5yWQ@
httpConnection.setRequestProperty("User-Agent","NetFox"); 'yq'J)
String sProperty = "bytes="+nStartPos+"-"; 1|PmZPKq9n
httpConnection.setRequestProperty("RANGE",sProperty); |>Xw"]b;
Utility.log(sProperty); $!msav
8/4Gr8o
X?F$jX|c
InputStream input = httpConnection.getInputStream(); "eH~/6A
//logResponseHead(httpConnection); 0 CJ4]mYl
,Cj8{s&;
YBX7WZCR
byte[] b = new byte[1024]; X> *o\
int nRead; fGv`.T_d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) kS>'6xXH
{ Q~'a1R
nStartPos += fileAccessI.write(b,0,nRead); 1qs~[7{C1
//if(nThreadID == 1) jaoGm$o>"F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7{vnhl(Z
} l7]$Wc[
J6!t"eB+
`R}D@
Utility.log("Thread " + nThreadID + " is over!"); oadlyqlw#
bDownOver = true; TwZvz[u
//nPos = fileAccessI.write (b,0,nRead); jH*+\:UP-
} Z{ntF
catch(Exception e){e.printStackTrace ();} tk^1Ga3
} AJ;Y Nb
} -S=Zsr\
]`D(/l'
y>S.B/d
//打印回应的头信息 X7sWu{n
public void logResponseHead(HttpURLConnection con) y*M,&,$
{ + R)x5
for(int i=1;;i++) Po[u6K2&
{ b'$j* N
String header=con.getHeaderFieldKey(i); u.gh04{5
if(header!=null) s0Ii;7fA{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @j$tpz
Utility.log(header+" : "+con.getHeaderField(header)); dXh@E7
else tR5zlm(}
break; =+{.I,g}g@
} b`n+[UCPtn
} 0EM`,?i .Q
+w/Ax[K
]lF'o&v]
public void splitterStop() 0k5Zl?
{ NDB]8C
bStop = true; Y*``C):K%
} @A6\v+ih
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[E(DGt
} M[_~7~4
l)z15e5X
-e%=Mpq.
/* uLb- NxQ-
**FileAccess.java I TJ>[c]x
*//文件访问(定位，写) +byw*Kk
package NetFox; Z`"UT#^SI
import java.io.*; @( 9#\%=
n/s!S &
<_ */
public class FileAccessI implements Serializable{ #rV=!j||
N)RWC7th{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a-Cp"pKlVY
RandomAccessFile oSavedFile; ;FZ\PxN
long nPos; (eJr-xZ/
5DyN=[b
f\~e&`PV
public FileAccessI() throws IOException z.Y7u3K.8
{ $EviGZFAaR
this("",0); .2 UUU\/5
} p>K'6lCa
A>>@&c:(
NfR,m]
public FileAccessI(String sName,long nPos) throws IOException h%+8}uywZ
{ 9qXHdpb#g"
oSavedFile = new RandomAccessFile(sName,"rw"); q9WdJ!-^X
this.nPos = nPos; j\dkv_L
oSavedFile.seek(nPos); Cqg}dXn'
} EemKYcE@Nr
5B2x# m|8
.&@|)u
public synchronized int write(byte[] b,int nStart,int nLen) 5Tu#o()
{ a2=wJhk
int n = -1; CM5A-R90
try{ d*A>P
oSavedFile.write(b,nStart,nLen); U"m!f*a
n = nLen; 0E\R\KO$>
} K:y q^T7
catch(IOException e) kOdS^-
{ &@+K%qW[e
e.printStackTrace (); mnmwO(.
} n+Ag|.,|
R@VO3zsW
-'}iK6
return n; G~B V^
} C4 Wdt
V'mpl
VsZ_So;
} LWQ BGiJj
s}z,{Y$-t
\~?s= LT
/* $s]@%6f
**SiteInfoBean.java jQ^Ib]"K
*/ so8-e
package NetFox; R3@iN&
T=R94
&9ZIf#R
public class SiteInfoBean { ]cA~%$c89s
A.h?#%TLL
F 5JgR-P
private String sSiteURL; //Site's URL @2$8o]et
private String sFilePath; //Saved File's Path >u/yp[Ky
private String sFileName; //Saved File's Name Bhs`Y/Ls-
private int nSplitter; //Count of Splited Downloading File _$cBI_eA7
5:PZ=jPR
b,`\"'1
public SiteInfoBean() iIF'!K=q
{//nSplitter的缺省值为5 0Gs]>B4r/
//default value of nSplitter is 5 NkJ^ecn%)
this("","","",5); 6,h<0j{
} /<2_K4(-{4
'H9~rq7
>lj3MNSH
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *&PgDAQ
{ jFc{$#g-
sSiteURL= sURL; %51pfuL
sFilePath = sPath; Uy_=#&jg
sFileName = sName; SeTU`WLEm
this.nSplitter = nSpiltter; 950b9Vn&
BxqCV%9o
p~b$+8#+
} Mzd}9x$'J
\'KzSkC8
#n7{ 3)
public String getSSiteURL() hJ@nW5CI
{ DXGO-]!!0
return sSiteURL; Z4!3I@yZ
} RW)C<g
<f6Oj`{f4
ex1ecPpN
public void setSSiteURL(String value) %Fv)$ :b
{ N#:"X;
sSiteURL = value; %xRS9A4
} @RP|?Xc{?
qSd $$L^
$3ILVT
public String getSFilePath() V_pBM
{ bsm,lx]bH^
return sFilePath; I}WJ0}R
} 7,zARWB!?
f/x "yUq
M@\'Y$)Y{
public void setSFilePath(String value) cOQy|v`KD,
{ -ZB"Yg$l
sFilePath = value; EHZSM5hu
} 0FOf *Lz
+0 MKh
[XXN0+ /
public String getSFileName() c0 |p34
{ Pa}vmn1$
return sFileName; l+6(|"md
} ^U}0D^jDeE
lI 1lP 1
{76!
public void setSFileName(String value) ^ne8~ ;Q
{ ?=kswf
sFileName = value; o3=kF
} L|LTsRIq
,X^_w g
8:xo ~Vc
public int getNSplitter() [JoTWouNU
{ aTsfl
return nSplitter; L])w-
} +pvJ?"J
ak`)>
wVDB?gy%#
public void setNSplitter(int nCount) k5D'RD
{ sE6J:m(
nSplitter = nCount; AvZ)1(
} dn_OfK
} 2-aYqMmT;
I})t
5#.\pR{Gd
/* Jr)`shJ"
**Utility.java sG2 3[t8
*/ (JW?azU
package NetFox; 1 ],, Ar5
4Z9wzQ>
Y,btL'[W
public class Utility { #Hi]&)p_
AijTT%
mo[<4Uks
public Utility() 0WE1}.J<
{ 2Fgt)`{!
{@__%=`CCS
Cfo 8gX*
} Tw;qY
yr2L
//线程睡眠 9zYiG3 d
public static void sleep(int nSecond) C_cs(}wi
{ qlITQKGG
try{ <3=qLm
Thread.sleep(nSecond); Du:p!nO
} An #Hb=
catch(Exception e) ywynx<Wg
{ !L. K)9I
e.printStackTrace (); tQ/ #t<4D
} lkH;N<U
} nIQ&gbfO
Fra>|;do
//日志 IAF;mv}'
public static void log(String sMsg) |"YA<e %
{ 1Uemsx%'k
System.err.println(sMsg); !Nl.Vb
} 9/1+BQ
)w2K&Zr0
=Y/fF
public static void log(int sMsg) u}}9j&^Xa
{ r}0C8(oq
System.err.println(sMsg); G/z\^Q
} PB(
} ]TBtLU3
R'I_xjC
/X^3=-{8
/* 7AO3-; l]
**TestMethod.java (#bp`Kih
*/ l{6` k<J(
package NetFox; y=9Dxst"V
n{^<&GWox
n^AP"1l8?0
public class TestMethod { (D>y6r>r
%l:|2s:
97Zk P=Cq
public TestMethod() n{64g+
{ ///xx/weblogic60b2_win.exe 9p2>`L
try{ Any Zi'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); VFl 1 f
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "7kgez#Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,@Fgr(?'`>
fileFetch.start(); QB/7/PW{H\
} Iz}2 ^
catch(Exception e){e.printStackTrace ();} h4aygc
jby~AJf%
lf%b0na?r
} xH<'GB)
d"H<e}D
aKv[
public static void main(String[] args) T?X^0UdJj
{ Es'-wr\Hm
new TestMethod(); (R_CUH
} zmf"I[)
} iV?` i
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