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)); i'9
} jW+L0RkX
for(int i=0;i<nEndPos.length-1;i++) mYzq[p_|j
{ j^~WAWbFh
nEndPos = nStartPos[i+1]; %@jv\J
} SQbnn"
nEndPos[nEndPos.length-1] = nFileLength; yN~: 3
} Lw.N3!e[
} vg1p{^N!
E8Wgm 8
KArnNmJ9
//启动子线程 eESJk14
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }3!.e
for(int i=0;i<nStartPos.length;i++) PV%7m7=x
{ z|SLH<~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n2H2G_-L[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %8+'L4
nStartPos,nEndPos,i); e&u HU8k*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %+9Mr ami
fileSplitterFetch.start(); 2FS,B\d
} G}\E{VvWh
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l$Y7CIH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %-:6#bz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l>M&S^/s j
nEndPos = " + nFileLength); @Tr8.4
// fileSplitterFetch[nPos.length-1].start(); ZUMzWK5Th
T{j&w%(z
@4b"0ne}h
//等待子线程结束 #sEbu^
//int count = 0; #.%;U' #O
//是否结束while循环 PZ;O pp
boolean breakWhile = false; MqI!i>
7Q.?]k&
T;}pMRd%
while(!bStop) *Ta*0Fr=9|
{ 0BIH.ZV#
write_nPos(); kf$0}T`
Utility.sleep(500); @$;"nVZ4v
breakWhile = true; M(S:&GOU
8\t~*@"
mY3x (#I
for(int i=0;i<nStartPos.length;i++) fN>o465I6
{ j4Cad
if(!fileSplitterFetch.bDownOver) H6*d#!
{ $3%EKi
breakWhile = false; I/MYS5}
break; K$\]\qG6
} VHB5
} A=|&N%lP'
if(breakWhile) [3rvRJ.
break; V5RfxWtm:
0*8[m+j1
y:Qo:Z~
//count++; !K1[o'o#
//if(count>4) #G^?4Za
// siteStop(); 1< ;<?
} :NO'[iE
dGcG7*EX
}}l04kN_
System.err.println("文件下载结束！"); -pc*$oe
} O6;7'
catch(Exception e){e.printStackTrace ();} 7WW@%4(
} #IyxH$
K9gfS V>]
4RNB\D
//获得文件长度 Hc4]2pf
public long getFileSize() HkEfBQmh
{ Qg9 N?e{z
int nFileLength = -1; Q5/".x^@
try{ 5B@+$D[0?3
URL url = new URL(siteInfoBean.getSSiteURL()); 4?,N;Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +=^10D
httpConnection.setRequestProperty("User-Agent","NetFox"); a4L8MgF&$-
3ePG=^K^
L*1C2EL/q
int responseCode=httpConnection.getResponseCode(); S!k cC-7
if(responseCode>=400) d?*=<w!A
{ \:\rkc9LI
processErrorCode(responseCode); sUcx;<|BC
return -2; //-2 represent access is error -D0kp~AO4N
} z'MOuz~Y
u:3~Ius
ZPY#<^WOzr
String sHeader; _CBG?
p0UR5A>p
Edc< 8-
for(int i=1;;i++) J O`S
{ :}v&TQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ">*PH}b
//Utility.log(in.readLine()); ub6=^`>h
sHeader=httpConnection.getHeaderFieldKey(i); &hEtVkK
if(sHeader!=null) 7g cr$&+e
{ JVFn=Mw
if(sHeader.equals("Content-Length")) _1f!9ghT\
{ \SS1-UbL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <|~X,g;f
break; <l(LQmM;
} lh&Q{t(+8
} G@ XKE17
else (u+3{Eb
break; ^i2W=A'P
} |[;9$Vn
} +HQX]t:Y
catch(IOException e){e.printStackTrace ();} Ua)ARi %
catch(Exception e){e.printStackTrace ();} B)O{+avu
(hS j4Cp
ds,NNN<HW
Utility.log(nFileLength); 9sifc<za
0{j]p^'<
u1xCn\
return nFileLength; hMh8)S
} <T+)~&g$
YN#i^(
/mX/ "~
//保存下载信息（文件指针位置） _$]3&P
private void write_nPos() >fJY
{ Lqb9gUJ:U
try{ Fx*iAH\e
output = new DataOutputStream(new FileOutputStream(tmpFile)); d:.S]OI0
output.writeInt(nStartPos.length); -uXf?sTV
for(int i=0;i<nStartPos.length;i++) (;;%B=
{ W~z 2Q so
// output.writeLong(nPos); +hI:5(_
output.writeLong(fileSplitterFetch.nStartPos); @r^a/]5D
output.writeLong(fileSplitterFetch.nEndPos); 9aFu51
} $DeHo"mg7m
output.close(); 8e:J{EG~
} $014/IB
catch(IOException e){e.printStackTrace ();} lM~ 3yBy
catch(Exception e){e.printStackTrace ();} OaY.T
} \C $LjSS-
oOlqlv
> L_kSC?
//读取保存的下载信息（文件指针位置） sa$CCQ
private void read_nPos() lk]q\yO_%
{ eW,{E)x:
try{ (pN:ETB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O%L]*vIr
int nCount = input.readInt(); j\iE3:94$
nStartPos = new long[nCount]; bfcQ(m5
nEndPos = new long[nCount]; jT>G8}h
for(int i=0;i<nStartPos.length;i++) byoP1F%
{ n]^zIe^6
nStartPos = input.readLong(); ul$k xc=N
nEndPos = input.readLong(); _GS_R%b
} +e}v)N
input.close(); 7ESSx"^B
} F_.rLgGY
catch(IOException e){e.printStackTrace ();} >zFk}/
catch(Exception e){e.printStackTrace ();} GdHFgxI
} r#rL~Rsd}
A[:0?Ez=
Ut.%=o;&[
private void processErrorCode(int nErrorCode) m/@ ;N,K
{ 9.u}<m
System.err.println("Error Code : " + nErrorCode); 4zyN>f|
} _ p%=RIR
uF,F<%d
X5@+M!`
//停止文件下载 |Hx#Uk#
public void siteStop() V>D8l @
{ 4eH:eCZze
bStop = true; T%74JRQ
for(int i=0;i<nStartPos.length;i++) {\zTE1X9
fileSplitterFetch.splitterStop(); LtIp,2GP&_
*-uA\
uH*moVw@5
} gySCK-(y
} :%G_<VAo!
//负责部分文件的抓取 o;#:%
**FileSplitterFetch.java lTb4quf8I
*/ dRj2%Q f
package NetFox; ?='2@@8;
4z<nJOEh[
FQY{[QvF~
import java.io.*; 4JQd/;
import java.net.*; )oqNQ'yZ
eXKpum~
FZL"[3
public class FileSplitterFetch extends Thread { Gak@Z!|
M3q%(!2
kU:ge
String sURL; //File URL R!&9RvNw
long nStartPos; //File Snippet Start Position 8XfhXm>~
long nEndPos; //File Snippet End Position atr0hmQ
int nThreadID; //Thread's ID u@&e{w~0
boolean bDownOver = false; //Downing is over +;r1AR1)x
boolean bStop = false; //Stop identical Qe,jK{Y< -
FileAccessI fileAccessI = null; //File Access interface rhff8C//'
1 S<E=7
5@QJ+@j|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {Kh^)oYdd
{ Fnqj^5
this.sURL = sURL; TAL,(&[s
this.nStartPos = nStart; ;|qbz]t2(
this.nEndPos = nEnd; "w7{,HP
nThreadID = id; 5Z;iK(>IX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3Z0ez?p+5
} 4,g_$)
\ -n&z;`
U:r^4,Mz*
public void run() r+TvC{
{ aH/8&.JLi
while(nStartPos < nEndPos && !bStop) \/XU v(
{ %f)%FN.S
?)NgODU
[0bp1S~
try{ ^8.s"4{
URL url = new URL(sURL); h`i*~${yg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @LSfP
httpConnection.setRequestProperty("User-Agent","NetFox"); B:)PUBb
String sProperty = "bytes="+nStartPos+"-"; P5Bva
httpConnection.setRequestProperty("RANGE",sProperty); g)dKXsy(F
Utility.log(sProperty); rX(Ol,&oP
`.i #3P
@\U;?N~k
InputStream input = httpConnection.getInputStream(); vzX%x ul
//logResponseHead(httpConnection); 5J-slNNCQ
J,G/L!Bp
>//yvkZ9,
byte[] b = new byte[1024]; M{z&h>
int nRead; u+lNcyp"MW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @[LM8 @:
{ G^ShN45
nStartPos += fileAccessI.write(b,0,nRead); :3N6Ej
//if(nThreadID == 1) VwN=AFk Oj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Tuz~T _M
} f_|pl^
ajCe&+
Z-j?N{3&
Utility.log("Thread " + nThreadID + " is over!"); 8B?*?,n5
bDownOver = true; %45*DT
//nPos = fileAccessI.write (b,0,nRead); %E8HLTEvl
} <=~*`eWV
catch(Exception e){e.printStackTrace ();} GX+Gqj.
} %)ri:Qq
} XqLR2d
,UYe OM2Ao
63`5A3rii
//打印回应的头信息 G>edJPfQ
public void logResponseHead(HttpURLConnection con) QsX`IYk
{ M1z ?E@kz
for(int i=1;;i++) <<DPer2
{ r}:Dg fn
String header=con.getHeaderFieldKey(i); %0p9\I
if(header!=null) `*o ko[\3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ip<~Y
Utility.log(header+" : "+con.getHeaderField(header)); sFPh?
else v}5||s!=
break; U:AB%gr[
} J``5;%TJp
} nt%fJ k
?7#{#sj
a|5<L
public void splitterStop() O]XgA0]
{ T|&u?
bStop = true; PYwGGB-
} :IO"' b
_'|C-j`u$
*V_b/Vt
} ef@F!s_fI
$a|>>?8
5g`J}@"k
/* #Vhr1;j
**FileAccess.java >guX,hx^
*//文件访问(定位，写) d(j g "@
package NetFox; [{0/'+;9
import java.io.*; '=H3Y_{oO
%J+ w9Z
+y_V$q$G
public class FileAccessI implements Serializable{ -k }LW4
TyvUdU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Qe0?n
RandomAccessFile oSavedFile; _H@8qR
long nPos; .NJ Ne
cSBS38>
B1j^qoC.5
public FileAccessI() throws IOException Y>{%,d#s_
{ E#A}2|7,g
this("",0); [s+FX5'K
} _&N:%;9uD
*Z+U}QhHD6
, {}S<^?]
public FileAccessI(String sName,long nPos) throws IOException |kF"p~s
{ T2A74>Nw
oSavedFile = new RandomAccessFile(sName,"rw"); 8.&P4u i
this.nPos = nPos; /!_FE+
oSavedFile.seek(nPos); J|@O4g
} )h]tKYx
f[*g8p
vl!o^_70(
public synchronized int write(byte[] b,int nStart,int nLen) &gP1=P,!
{ ;Za^).=
int n = -1; sHPlNwyy
try{ +f}w+
oSavedFile.write(b,nStart,nLen); u`XZtF<vf
n = nLen; gk}.LE
} LWxP}? =
catch(IOException e) S#0C^
{ &Z}}9dd
e.printStackTrace (); pf#R]
} Abpzf\F
kaRjv
l}FA&c"
return n; W6)XMl}n
} x&N@R?AG1
gF]IAZCi
P@<K&S+f
} " ;o,D
@7sHFwtar?
,D.@6bJW
/* iA4VT,
**SiteInfoBean.java .B!L+M< [
*/ 3!Mb<W.3
package NetFox; - v=ndJ.
1`1Jn*|TI
%+dRjG~TB
public class SiteInfoBean { 6|Crc$4l
"Z"`X3,-z
BPy pA$
private String sSiteURL; //Site's URL AY]rQ:I
private String sFilePath; //Saved File's Path )LL.fPic
private String sFileName; //Saved File's Name S,s") )A1
private int nSplitter; //Count of Splited Downloading File (9)uZ-BF,
[C3wjYi
D7v.Xq|
public SiteInfoBean() }cIj1:
{//nSplitter的缺省值为5 t?p>L*
//default value of nSplitter is 5 $wcV~'fM
this("","","",5); 9Z:pss@
} W,%qL6qV
zB"y^g
"9RW<+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5(DnE?}vo
{ rD>q/,X=\
sSiteURL= sURL; _z3^.QP
sFilePath = sPath; [5]* Be
sFileName = sName; Ct0%3]<J
this.nSplitter = nSpiltter; ]2z Gb5s"
Tt{ft?H71
.Zx7+`i
} !)OA7%3m
i,/Q.XL
8yGo\\=T
public String getSSiteURL() aVn+@g<.
{ {z# W-
return sSiteURL; PR>%@-Vgj
} L ~$&+g
P1ynCe
w.Kp[
public void setSSiteURL(String value) ."j*4
{ ZQ~EaI9R
sSiteURL = value; .a|ROjd!
} XOzZtt
&^ =Y76
(XQl2C
public String getSFilePath() >&|/4`HSB
{ %U$%x
return sFilePath; (PnrY~9
} IUy5=Sl
5{#ya2
~ [=2d a
public void setSFilePath(String value) T)cbpkH4
{ gk"J+uM
sFilePath = value; 9riKSp:5
} ="[6Z$R
m6 a@Y<
Va\?"dH>M
public String getSFileName() LYS[qLpf
{ Q#I?nBin
return sFileName; Y.o-e)zX
} ptpu u=3"
}x:nhy`
uX,ln(9I*H
public void setSFileName(String value) @,TCg1@QJ
{ btB> -pT
sFileName = value; K9UWyM<(2C
} :sekMNM
G;bE_O
Y.8mgy>
public int getNSplitter() mr`EcO0
{ zC$(/nZ
return nSplitter; N:rnH:g+:
} 12yX`9h>
2aGK}sS6
u}KEH@yv
public void setNSplitter(int nCount) <k2]GI-}h
{ nL* SNQ_
nSplitter = nCount; ,m.IhnCV\
} RkBbu4uQ-
} !CuLXuM
"ZFK-jn/
Y&`nB,'
/* qXQ7Jg9
**Utility.java 2o-Ie/"d\
*/ X6: c-
package NetFox; jiAN8t*P
Yc1ve
m_1BB$lyP2
public class Utility { MQGR-WV=5
mkt%|Kb.
/bv4/P
public Utility() {AqPQeNgz
{ 0~j0x#
V$<5`
FG5t\!dt<
} )3~):+
k-\RdX)E
//线程睡眠 }KwL_\>&f
public static void sleep(int nSecond) mw&)j R$&
{ giz#(61j^
try{ tsu Mt
Thread.sleep(nSecond); DU-&bm
} G2}e@L0
catch(Exception e) +eD+Z.{
{ =`6_{<&
e.printStackTrace (); xA2"i2k9
} ,_2ZKO/k$
} :*/`"M)'
Ta3qEVs
//日志 ln6Hr^@5
public static void log(String sMsg) `>cBR,)r
{ weky 5(:
System.err.println(sMsg); "i;c)ZP
} 2hI|]p
*_7%n-k
V0x;*)\PYm
public static void log(int sMsg) 8z h{?0
{ vMV}M%~
System.err.println(sMsg); &*N;yW""f
} aM|^t:
} s!j[Ovtx
_]whHS+
6vQCghI
/* qKg*/)sD(
**TestMethod.java 5L4{8X0X8
*/ 3KW4 ]qo~
package NetFox; gK8{=A0c
X]OVc<F
xMu[#\Vc
public class TestMethod { 5J4'\M
69$[yt>KYz
hln.EAW'Yc
public TestMethod() i#Y[I"'
{ ///xx/weblogic60b2_win.exe mew,S)dq!
try{ @H^Yf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +bw>9VmG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Bqd'2HQd
SiteFileFetch fileFetch = new SiteFileFetch(bean); af<R.
fileFetch.start(); 2\p8U#""
} 9zKrFqhNo
catch(Exception e){e.printStackTrace ();} r2]KP(T8|
Gd8FXk,.!
\'gb{JO
} "NgfdLz
A+&^As2
9=J+5V^qD<
public static void main(String[] args) [Cx'a7KWL
{ LzW8)<N
new TestMethod(); 0//?,'.
} K*_5M
} $&Ntdn
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