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)); <lB2Nv-,
} %uo8z~+
for(int i=0;i<nEndPos.length-1;i++) j#f/M3
{ OmuE l>
nEndPos = nStartPos[i+1]; )?[2Y%P
} "1s ]74
nEndPos[nEndPos.length-1] = nFileLength; )FwOg;=3M"
} 9we];RYK
} w}1IP-
<l1/lm<#
`:lcN0n
//启动子线程 7Q/H+)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mywxV
for(int i=0;i<nStartPos.length;i++) k$v7@|Aw
{ Qb@j8Xa4[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1le9YL1_g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZTTA??}Y
nStartPos,nEndPos,i); q-t%spkl
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eSoX|2g
fileSplitterFetch.start(); vE9"1M
} b#I,Z+0ry
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '\{ OQH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6Y[&1c8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s>;"bzzq
nEndPos = " + nFileLength); oRd{?I&NY
// fileSplitterFetch[nPos.length-1].start(); <vl(a*4a
)[hs#nKTh
^(&2
//等待子线程结束 ^RnQX#+
//int count = 0; Y<;C>Rs
//是否结束while循环 ]/!*^;cY(
boolean breakWhile = false; Q+f|.0r
!}c D e12
HV!P]82Pa
while(!bStop) Jha*BaD~N
{ %;4#?.W8
write_nPos(); _3 [E$Lg
Utility.sleep(500); wSjy31
breakWhile = true; 3wN4kltt
t>]W+Lx#
0(&uH0x
for(int i=0;i<nStartPos.length;i++) 5M\0t\uEn
{ Mxz X@GBX
if(!fileSplitterFetch.bDownOver) 4oF,;o+v\4
{ 36'J9h\
breakWhile = false; rKPsv*w
break; 2;]tItd1
} lJa-O
} toF6 Z
if(breakWhile) 'NWvQR<X
break; BfCib]V9C
AkjoD7.*
h1>.w pr
//count++; p,WBF
//if(count>4) Rt%Dps%
// siteStop(); f~d=1
} .~'q yD2V
Ge$&k
NO*~C',cI/
System.err.println("文件下载结束！"); _)-2h[
} &\?{%xj
catch(Exception e){e.printStackTrace ();} N cHCcc
} J'cE@(US
5YZ\@<|rH
@W+8z#xr'
//获得文件长度 21$^k5
public long getFileSize() w;VUP@Wm
{ m";8 nm
int nFileLength = -1; "~C\Z} ;
try{ |RpZr!3V
URL url = new URL(siteInfoBean.getSSiteURL()); qyyLU@hd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ahd{f!
httpConnection.setRequestProperty("User-Agent","NetFox"); M]\"]H?
oQyMs>g
&m(eMX0lU
int responseCode=httpConnection.getResponseCode(); 5NSXSR9c
if(responseCode>=400) Rpcnpo
{ 2b {Y1*
processErrorCode(responseCode); 'H1"z!]
return -2; //-2 represent access is error +$~HRbo
} AO$aWyI
P\c0Q;){h"
(I`<;
String sHeader; hy"p8j7_
LY0/\Z"N
etW-gbr
for(int i=1;;i++) I |D]NY^
{ a(o[ bH.|;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); iEFS>kL8e
//Utility.log(in.readLine()); n O}x,sG2'
sHeader=httpConnection.getHeaderFieldKey(i); jM@@N.
if(sHeader!=null) AMgvk`<f
{ 43J8PMY
if(sHeader.equals("Content-Length")) }=3W(1cu-
{ p|Fhh\,*`X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]*S_fme
break; uuhvd h=
} 1_W5@)
} Qe/=(P<
else Hi{!<e2
break; L3Q1az!Ct
} _Q;M$.[zyR
} I(WND/&
catch(IOException e){e.printStackTrace ();} $PbN=@
catch(Exception e){e.printStackTrace ();} Y@'1}=`J
#iGz&S3iN$
P3XP=G`E
Utility.log(nFileLength); NOmSLIgt7
j1toV$)P
1/qiE{NW
return nFileLength; y+iuA@WCv
} 0H.B>:pv
kqAQrg]n
&sA6o"h~
//保存下载信息（文件指针位置） ~pSD|WX
private void write_nPos() o:Z*F0qm
{ .J\U|r
try{ >-y&k^a=
output = new DataOutputStream(new FileOutputStream(tmpFile)); El&pux2
output.writeInt(nStartPos.length); A[':O*iB
for(int i=0;i<nStartPos.length;i++) &<i>)Ss
{ U7fE6&g
// output.writeLong(nPos); l 0b=;^6
output.writeLong(fileSplitterFetch.nStartPos); >|I3h5\M
output.writeLong(fileSplitterFetch.nEndPos); ;/{Q4X{
} 4_I,wG@
output.close(); &(^>}&XS.<
} "Lpt@g[HF
catch(IOException e){e.printStackTrace ();} m~NWY$oI9[
catch(Exception e){e.printStackTrace ();} Ez1*}
} <u($!ATb
9'8oOBqm3%
$X&OGTlw^
//读取保存的下载信息（文件指针位置） E.% F/mM
private void read_nPos() 2Nl("e^kJr
{ C1rCKKh
try{ d`nS0Tf'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r@<;
int nCount = input.readInt(); +#H8d1^5
nStartPos = new long[nCount]; B 9Mwj:)}
nEndPos = new long[nCount]; 3S2'JOTY
for(int i=0;i<nStartPos.length;i++) i+cGw
{ o-'i)pp
nStartPos = input.readLong(); /~tfP
nEndPos = input.readLong(); 6k3l/~R
} ;<X3AhF
input.close(); '}YXpB
} x?<5=,
catch(IOException e){e.printStackTrace ();} a@r K%Iff
catch(Exception e){e.printStackTrace ();} D3lYy>~d5;
} 'IW+"o
kWz%v
>`\*{]
private void processErrorCode(int nErrorCode) Y@\5gZ&T
{ =,]J"n8|v
System.err.println("Error Code : " + nErrorCode); ft6^s(t
} A0X0t
#"yf^*wX
7ER 2h*
//停止文件下载 ?Ru`ma\;
public void siteStop() I2DmM"-|
{ aQmL=9
bStop = true; d=KOV;~);
for(int i=0;i<nStartPos.length;i++) \j;uN#)28
fileSplitterFetch.splitterStop(); CGe'z
p+7BsW.l
!^fJAtCN]
} \mu9ikZ<
} XP^6*}H.*
//负责部分文件的抓取 7~Ga>BK
**FileSplitterFetch.java 1=a}{)0h
*/ TxCQGzqe
package NetFox; k"7eHSy,
`U3
G\p; bUF
import java.io.*; rlIEch^wZ
import java.net.*; t3>rf3v
YPy))>Q>cK
hw'2q9J|
public class FileSplitterFetch extends Thread { S7q&|nI
"qm>z@K
">QY'r
String sURL; //File URL uWInx6p
long nStartPos; //File Snippet Start Position .nH /=
long nEndPos; //File Snippet End Position kZ.3\
int nThreadID; //Thread's ID 66Xt=US
boolean bDownOver = false; //Downing is over *&0Hz{|
boolean bStop = false; //Stop identical 9|WWA%p
FileAccessI fileAccessI = null; //File Access interface ?^vZ{B)&0E
J| '(;Ay4u
yrs3`/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X[~CLKH(
{ LG|,g3&
this.sURL = sURL; LI<5;oE;
this.nStartPos = nStart; ;MJ1Q
this.nEndPos = nEnd; JAz;_wS(k
nThreadID = id; ZO1J";>u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5l}h8So4
} Zn0fgQd
g\)z!DQ]
qi2dTB
public void run() iP%=Wo.
{ F]*-i 55S
while(nStartPos < nEndPos && !bStop) 7&)F;;H
{ R*0F)M
6v#G'M#r
!v L:P2
try{ W8NA.
URL url = new URL(sURL); iIw ea`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i?/?{p$#a-
httpConnection.setRequestProperty("User-Agent","NetFox"); $bosGG
String sProperty = "bytes="+nStartPos+"-"; ~&:R\
httpConnection.setRequestProperty("RANGE",sProperty); ECzNByP
Utility.log(sProperty); \(FDR
_64@zdL+
-JENY|6
InputStream input = httpConnection.getInputStream(); mD)O\.uA
//logResponseHead(httpConnection); @GtZK
vNSf:5H$
TMCA?r%Y\
byte[] b = new byte[1024]; RWo B7{G
int nRead; !S-U8KI|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [ d7]&i}*|
{ <pUou
nStartPos += fileAccessI.write(b,0,nRead); c7IR06E
//if(nThreadID == 1) |u;PU`^-z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ItPK
} 3= zQ U
*KH@u
eBIR*TZ):
Utility.log("Thread " + nThreadID + " is over!"); r_E)HL/A
bDownOver = true; U.'@S8
//nPos = fileAccessI.write (b,0,nRead); 8Jj0-4]
} 3]es$Jy
catch(Exception e){e.printStackTrace ();} ]?`p_G3O
} x 4</\o
} F5MPy[
9lJj/
[B @j@&
//打印回应的头信息 ug"<\"
public void logResponseHead(HttpURLConnection con) H;|:r[d!
{ |uBC0f
for(int i=1;;i++) 3og$'#6P
{ H`lD@q'S
String header=con.getHeaderFieldKey(i); "@w%TcA
if(header!=null) E}9ldM=]s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ](:FW '-
Utility.log(header+" : "+con.getHeaderField(header)); c|( ?
else =>\-ma+
break; /+`<X%^U
} {taVAcb
} L_K\i?
_C,@eu"9V
f\U&M,L\'
public void splitterStop() @[lc0_b
{ oImgj4C2L
bStop = true; AWXpA1(
} ?lN8~Ze
M2Fj)w2
M.N~fSJ
} wKS-O%?
gam#6 s
%`1CE\f
/* 2RUR=%C
**FileAccess.java EvQwGt1)P
*//文件访问(定位，写) ZNpExfGEU
package NetFox; yPh2P5}H>
import java.io.*; Ca@=s
QsJW"4d
bH&)rn
public class FileAccessI implements Serializable{ bTQa'y`3
g+ 1=5g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /:{_|P\
RandomAccessFile oSavedFile; D>b5Uwt
long nPos; <-B"|u
]Bd3d%
|EV\a[
public FileAccessI() throws IOException !FO^:V<|5
{ #lshN,CPm
this("",0); 6mpg&'>
} pNE\@U|4E
@PoFxv
fCf#zV[
public FileAccessI(String sName,long nPos) throws IOException K}E7|gdG
{ h<'5q&y
oSavedFile = new RandomAccessFile(sName,"rw"); Oqpl2Y"/
this.nPos = nPos; -jtC>_/
oSavedFile.seek(nPos); u@_!mjXQ
} t_>bTcsU
dEd]U49u
~@uY?jr
public synchronized int write(byte[] b,int nStart,int nLen) TF0-?vBWh
{ hdr}!wV
int n = -1; JV]u(PL
try{ IgVo%)n
oSavedFile.write(b,nStart,nLen); [}ZPg3Y
n = nLen; G</I%qM
} vV6Lp
catch(IOException e) SU%rWH
{ (21 W6
e.printStackTrace (); tdnXPxn[
} 2iPmCG
$rpTs?j*K$
]r6BLZ[%
return n; leES YSY:
} ke9QT#~p!-
Fb|e]?w
:x""E5H
} &H4uvJ_<
V(2j*2R!
_@/C~
/* _h1 HuL
**SiteInfoBean.java MO~~=]Y'
*/ ..]*Ao2
package NetFox; +eBMn(7Cgv
A!ioji+{[
{;iHYr-zs
public class SiteInfoBean { /}nrF4S
tSb?]J
uqa4&2(I=j
private String sSiteURL; //Site's URL UROj9COv
private String sFilePath; //Saved File's Path ?H[5O+P[
private String sFileName; //Saved File's Name 8{G?92 {rN
private int nSplitter; //Count of Splited Downloading File t$H':l0
pdi=6<?bd
6/[Z178m
public SiteInfoBean() ^5;vx
{//nSplitter的缺省值为5 T1(j l)
//default value of nSplitter is 5 &8]#RQy{f
this("","","",5); UEEBWzH
} 7bonOt Y
X%a;i6pq
b$?Xn{Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .lvI8Jf~X
{ uS,p|}Q&
sSiteURL= sURL; rmPne8D=c(
sFilePath = sPath; lk[G;=K:.
sFileName = sName; B0)`wsb_
this.nSplitter = nSpiltter; 8 _4l"v p
oI_oz0nHk
-v;n"Zy1
} F<yy>Wf
q}<.x8\
1iNsX\M
public String getSSiteURL() oNuPP5d[]
{ \6SMn6a4
return sSiteURL; PG6[lHmi
} X(GmiH /E
C#Hcv*D
~5r=FF6
public void setSSiteURL(String value) I(OAEIz
{ <H5n>3#pH
sSiteURL = value; aFRTNu/r
} 9Qzjqq:"Li
y Y>-MoF/t
mW~i c
public String getSFilePath() u/gm10<OWa
{ zBk_-'z
return sFilePath; _m9~*
} b:P\=k]8#
2Vp>"
X,RT<GNNb
public void setSFilePath(String value) (TEo_BW|+
{ 87^:<\pp
sFilePath = value; \npz.g^c_
} W\it+/
!}>eo2$r^
F2IC$:e M
public String getSFileName() 8yE!7$Mj
{ l60ikc4$I
return sFileName; g!1I21M1~
} Mn]}s:v
G*i.a*9<)
?SC3Vzr
public void setSFileName(String value) uu}a:qrY
{ 1P_Fe[8
sFileName = value; 5ZnSA9?
} O6yP qG*j
$d'CBsu|<
{]&R8?%
public int getNSplitter() JAc@S20v\
{ .Qd}.EG
return nSplitter; 1^aykrnQ>
} p{NPcT%&
^DBD63N"
L~*u4
public void setNSplitter(int nCount) L)q`D2|'
{ W|;nJs:e
nSplitter = nCount; o g_Ri$x8
} 6|QTS|!
} Js/N()X
BSN6|W
aT&t_^[]
/* GF&_~48GD
**Utility.java XmP;L(wa
*/ avlqDi1l
package NetFox; I$n+DwKcN
^>-+@+( r
iwUv`>l&
public class Utility { PmHd9^C
]de\i=?|
Ujf,6=M
public Utility() /K f L+"^|
{ iBucT"d]
5i6VZv
T-^0:@5o9
} sr\cVv")
UanEzx%
//线程睡眠 W/sY#"
public static void sleep(int nSecond) RF:04d
{ @9aGz6k+
try{ h{I`7X
Thread.sleep(nSecond); gt'*B5F(
} 47KNT7C
catch(Exception e) 8+ov(B;(
{ GSP?X$E
e.printStackTrace (); YNI;h%w
} yx2z%E
} YV-j/U{&
1DUb [W8
//日志 a~,Kz\Tt
public static void log(String sMsg) F'1k<V?
{ sMP:sCRC
System.err.println(sMsg); #00D?nC
} ^ESUMXb
`g--QR
R }1W
public static void log(int sMsg) .@@an;C
{ $%Z3;:<Uf-
System.err.println(sMsg); *#zS^b n
} m~;B:LN<
} CI^[I\$&
\0nlPXk?G
h(nj,X+
/* >zQOK-
**TestMethod.java 88+ =F XG
*/ =5?.'XMk
package NetFox; `%Q&</X
wqP2Gw7jh6
>VP5vkv=
public class TestMethod { b:1 L@8s;
/[%w*v*'
okstY4f'
public TestMethod() p-xd k|'[
{ ///xx/weblogic60b2_win.exe D^|9/qm$
try{ w//omF'`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .%IslLZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g8RPHjvZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); W!91tzs:
fileFetch.start(); /D'M24
} ?_%u)S*g
catch(Exception e){e.printStackTrace ();} ya.n'X14
xz8G}Ku
FIS "Z(
} {rDq_^
JGis"e
s9i|mVtm8
public static void main(String[] args) q*bt4,D&Es
{ tb,9a!?
new TestMethod(); P\AqpQv
} t+O e)Ns
} ,:UX<6l R
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