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)); H @_eFlT t
} Bv2z4D4f+
for(int i=0;i<nEndPos.length-1;i++) +L^A:}L(
{ (iHf9*i CV
nEndPos = nStartPos[i+1]; AeNyZ[40T
} v(qV\:s}m
nEndPos[nEndPos.length-1] = nFileLength; g,00'z_D
} B`g<Ge~
} Q mb[ e>
fQ=&@ >e
&Pmc"9Rl
//启动子线程 )p^m}N 6M]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4(` 2#
for(int i=0;i<nStartPos.length;i++) 9X 5*{f Y
{ hg%@W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >{O[t2&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e#l*/G*,
nStartPos,nEndPos,i); g0^~J2sDd
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @?<N +qdH>
fileSplitterFetch.start(); &/B2)l6a
} aDm-X r
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *]{9K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mr:kn0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j#*asGdp#J
nEndPos = " + nFileLength); 9F2P(aS
// fileSplitterFetch[nPos.length-1].start(); z5x,fQw6O
X@6zI-Y%
X% Spv/8{
//等待子线程结束 S/@dkHI'
//int count = 0; B'G*y2UnG
//是否结束while循环 /2g)Z!&+L
boolean breakWhile = false; %k/ k]:s
IUh5r(d 68
S[W9G)KWp
while(!bStop) '_q: vjX
{ Z:\;R{D
write_nPos(); @D.R0uM
Utility.sleep(500); ?RgU6/2
breakWhile = true; s=H/b$v
F|]o9&/<]
ATYQ6E[{MV
for(int i=0;i<nStartPos.length;i++) AIvL#12
{ 7,V!Iv^X
if(!fileSplitterFetch.bDownOver) g5kYyE
{ OmTZ-*N
breakWhile = false; 09}f\/
break; Bq$e|t)'
} -4*'WzWr
} s=^r/Sz902
if(breakWhile) z;fd#N:
break; ~pd1)
bR>o!(M'Z\
Vu|Br
//count++; uPv;y!Lsa@
//if(count>4) 9#Aipu\
// siteStop(); m wRLzN
} ,xtKPA
.LXh]I*
L|]w3}ZT@
System.err.println("文件下载结束！"); <?q&PCAn^
} YLA557~
catch(Exception e){e.printStackTrace ();} ]YisZE4s
} RE`J"&
egxJ3.
)Dk0V!%N
//获得文件长度 1jUhG2y
public long getFileSize() rZ8Y=) e
{ @\%)'WU
int nFileLength = -1; 3PvZ_!G
try{ h}anTFKP
URL url = new URL(siteInfoBean.getSSiteURL()); w-0O j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RvyBg:Aj5
httpConnection.setRequestProperty("User-Agent","NetFox"); l6&v}M
C>w9 {h
1K? & J2
int responseCode=httpConnection.getResponseCode(); !^>LOH>j
if(responseCode>=400) AhbT/
{ ADLa.{
processErrorCode(responseCode); 1c<CEq:?e%
return -2; //-2 represent access is error 66^1&D"
} c:h.J4mv
Ac5o K
4i[v ew
String sHeader; &J6o$i
m'Ekp
5I8FD".i
for(int i=1;;i++) [x$eF~Kp
{ -CU7u=*b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); O, ``\(P
//Utility.log(in.readLine()); Kh:#S|
sHeader=httpConnection.getHeaderFieldKey(i); hSx+{4PZ
if(sHeader!=null) $+lz<~R
{ 68'-1}
if(sHeader.equals("Content-Length")) lry&)G=5
{ JGSk4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u'$yYzBE
break; m]-v IUpb
} }QWTPRn
} RKoP6LGw
else T}w*K[z $
break; AjL?Qh4
} 6uCk0 B|
} 7'{Yz
catch(IOException e){e.printStackTrace ();} r'9=kx
catch(Exception e){e.printStackTrace ();} Y6;0khp
|z(Ws
|oBdryi
Utility.log(nFileLength); VeN&rjc
T4HoSei
OU)p)Y_z
return nFileLength; mf*9^}l+Zn
} {x&jh|f`g
*&hXJJ[+
&-8-xw#.
//保存下载信息（文件指针位置） ~P]HG;$?n
private void write_nPos() qa0JQ_?o]
{ r_g\_y7ua
try{ ^7~SS2t!
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6wpND|cT
output.writeInt(nStartPos.length); 0'\FrG
for(int i=0;i<nStartPos.length;i++) k@t,[
{ PO%yWns30o
// output.writeLong(nPos); g<hv7?"[
output.writeLong(fileSplitterFetch.nStartPos); p+`*~6Jj/
output.writeLong(fileSplitterFetch.nEndPos); '.h/Y/oz
} /SqFP L]
output.close(); cT>z
} U3_yEvZ
catch(IOException e){e.printStackTrace ();} q*RaX 4V
catch(Exception e){e.printStackTrace ();} ltr;pc*)
} F"m}mf
bW 86Iw
Iu1Sj`A
//读取保存的下载信息（文件指针位置） 0IPhVG~#
private void read_nPos() t7!>5e)C}
{ 4M0v1`k
try{ ZB^4(F')H
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :E>n)_^
int nCount = input.readInt(); >Rki[SNb-b
nStartPos = new long[nCount]; ,$6MM6W;-F
nEndPos = new long[nCount]; #hE3~+i
for(int i=0;i<nStartPos.length;i++) o$blPTN
{ ,I2reG
nStartPos = input.readLong(); zFdz]z3
nEndPos = input.readLong(); 3U9+l0mBa
} B1d%#
input.close(); }d~FTre
} >Dp6@%
catch(IOException e){e.printStackTrace ();} X^ ^?}>t[
catch(Exception e){e.printStackTrace ();} ^zWO[$n}tP
} }%>$}4 ,
QnP?;
' ! UF&
private void processErrorCode(int nErrorCode) q| =q:4_L
{ |Z7bd^
System.err.println("Error Code : " + nErrorCode); Sj{rvW
} @'<j!CqQ o
0ZID @^
bZOy~F|
//停止文件下载 .f92^lu9
public void siteStop() }_kI>
{ 5k%N<e``
bStop = true; y8~)/)l&
for(int i=0;i<nStartPos.length;i++) 6rN5Xf cS
fileSplitterFetch.splitterStop(); dT,m{[+
S~a:1 _Wl
P"PeLB9K
} K_lL\
} Wse*gO
//负责部分文件的抓取 ZnhuIAAG
**FileSplitterFetch.java KEVy%AP=*h
*/ <C.$Db&9
package NetFox; RkH oT^
qiKtR
5.K$ X$+7}
import java.io.*; ^`>Ysc(@&
import java.net.*; zWmo OnK
l3pW{p
9y|&T
public class FileSplitterFetch extends Thread { kJ<Xq
f/[?5M[
;AL@<,8
String sURL; //File URL /DG`Hg
long nStartPos; //File Snippet Start Position U9p.Dh~)vG
long nEndPos; //File Snippet End Position KGE-RK
int nThreadID; //Thread's ID -TU{r_!Z(
boolean bDownOver = false; //Downing is over mKFHT
boolean bStop = false; //Stop identical fddbXs0Sn
FileAccessI fileAccessI = null; //File Access interface QWW7I.9r
(Q]Y> '
p|9ECdU>;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dG~B3xg;5i
{ vkd<l&zD
this.sURL = sURL; RAuAIiQ
this.nStartPos = nStart; K9N0kBJ0<
this.nEndPos = nEnd; >->xhlL*
nThreadID = id; >*i8RqU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D)~nAkVq
} HAUTCX
"1`i]Y\'
M Xt +
public void run() WWs[]zr
{ 6!Ji>h.Ak
while(nStartPos < nEndPos && !bStop) pS@VLXZP
{ gK#fuQ$hH
Jgv>$u
-2na::<K
try{ O7'^*"S
URL url = new URL(sURL); H"RF[bX(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #z^1)7
httpConnection.setRequestProperty("User-Agent","NetFox"); xE-`Bb
String sProperty = "bytes="+nStartPos+"-"; 6k=Wt7C
httpConnection.setRequestProperty("RANGE",sProperty); ;YXrG
Utility.log(sProperty); ,N|R/Vk$+E
9oxf)pjw
]-Y]Q%A4
InputStream input = httpConnection.getInputStream(); Rb}&c)4
//logResponseHead(httpConnection); ^`r|3c0
[BR}4(7
RJsG]`
byte[] b = new byte[1024]; `"=L
int nRead; u-M$45vct
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )E~\H+FP6
{ ?O>JtEz~lQ
nStartPos += fileAccessI.write(b,0,nRead); L\?g/l+k
//if(nThreadID == 1) W;g+R-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); . N} }cJq
} @NwM+^
f{5|}PL
SU}oKii /
Utility.log("Thread " + nThreadID + " is over!"); AXv;r<
bDownOver = true; iGeT^!N
//nPos = fileAccessI.write (b,0,nRead); W!0
} bOIM0<(h
catch(Exception e){e.printStackTrace ();} ,Yprk%JT
} pW^ ?g|_}
} Y*`A$
I4X+'fW,
u{nWjqrM*5
//打印回应的头信息 n6UU6t{
public void logResponseHead(HttpURLConnection con) uZ?CVluP
{ 70*iJ^|
for(int i=1;;i++) U <$xp
{ nV xMo_
String header=con.getHeaderFieldKey(i); |afK"N
if(header!=null) J8?6G&0H
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o-<_X&"a|5
Utility.log(header+" : "+con.getHeaderField(header)); M "P
else Y+`-~ 88
break; BRzWZq%r3
} ggsi`Z{j?
} rxI&;F#
:w_1J'D}
s=Q*|
public void splitterStop() '\E{qlI
{ HYnqx>L ~
bStop = true; {1U*:@j
} *k]S{]Y
12'(MAP
z2q5f:d8
} [QN7+#K,
8*~:gZ7:
]S aH/$
/* pV|?dQ
**FileAccess.java $M<4Bqr
*//文件访问(定位，写) Zy3&Zt
package NetFox; 4lf36K,
import java.io.*; m7eIhmP
$D\l%y/C
SFgIY]
public class FileAccessI implements Serializable{ bYB}A:
&j@J<*k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5Zm_^IS
RandomAccessFile oSavedFile; l@J|p#0q
long nPos; RGuHXf
j3-6WUO
;fME4Sp
public FileAccessI() throws IOException GE+csnA2
{ K0H!Ds9
this("",0); J6Nw-qF
} 'wnY>hN
"?&bh@P&
29657k8
public FileAccessI(String sName,long nPos) throws IOException #TwE??ms
{ ]3u'Qv}o
oSavedFile = new RandomAccessFile(sName,"rw"); ,(W98}nB
this.nPos = nPos; CuO*>g^K[
oSavedFile.seek(nPos); UKQ&TV}0
} 2.2a2.I1
3C[4!>|
3Wxtxk._E
public synchronized int write(byte[] b,int nStart,int nLen) :bDn.`KG#
{ {^MAdC_
int n = -1; xKzFrP;/{
try{ 5T3>fw2G
oSavedFile.write(b,nStart,nLen); t%B!\]
n = nLen; RAQ;O
} '#::ba[9w
catch(IOException e) J}KktD@!O
{ 8"UG&wLT
e.printStackTrace (); R:^?6f<Z}
} +p<R'/
=>%%]0
5(`GF|
return n; -gGK(PIf
} !TZ/PqcE
CyDf[C)=
lfeWtzOf
} m1i$>9,
n<&R"89
9<CUsq@i:
/* EXzNehO~e
**SiteInfoBean.java gc)3
*/ 6WcbJ_"mq
package NetFox; ''Ec-b6Q-
>F_Ne)}qTQ
Qug'B
public class SiteInfoBean { |o) _=Fx
.3&OFM
x#mk[SV
private String sSiteURL; //Site's URL IjAity.Xrq
private String sFilePath; //Saved File's Path zNJyF;3
private String sFileName; //Saved File's Name ulo7d1OVkJ
private int nSplitter; //Count of Splited Downloading File =PM#eu
v 8a
y'/9KrV T
public SiteInfoBean() CoXL;\
{//nSplitter的缺省值为5 IOqyqt'
//default value of nSplitter is 5 XPTB,1g+f
this("","","",5); G_4P)G3H
} l #z`4<
=@XR$Uud6
}"H900WE|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $m oa8
{ ^BTNx2VHf
sSiteURL= sURL; gRI|rDC)B
sFilePath = sPath; nDw9
sFileName = sName; VSFl9/5?
this.nSplitter = nSpiltter; {_}"USS
--)[>6)I
8}T3Fig,q
} bkIA:2HX
EA#!h'-s
L-gF$it\*b
public String getSSiteURL() E|3aiC,5
{ (9|K}IM:
return sSiteURL; ^IkMRlJh%
} h1)\.F4G
^ ?9 ~R"
Av]N.HB$
public void setSSiteURL(String value) -~ Q3T9+
{ t}l<#X5
sSiteURL = value; O0YGjS|d
} =@l5He.]&
J<@]7)|U
CFxs`C^
public String getSFilePath() >i E
{ \vQ (
return sFilePath; &>+Z$ZD
} r:-WfDz.
Z3{Qtysuv3
3i~{x[Jc
public void setSFilePath(String value) r'?&VS-Cj
{ t$iU|^'uV
sFilePath = value; D40VJ3TUc
} gk%ye&:f
!!%F$qUd\
Wfy+7$14M
public String getSFileName() hp}8 3.oA
{ O0RQ}~$'m
return sFileName; 5]+eLKXB
} &>{L"{
| 'G$}]H
v}@6"\
public void setSFileName(String value) GssoT<Y)Z
{ zv@o-R$l
sFileName = value; o\[nGf C&
} `#F>?g$2
~<LI p%5(
b\mN^P~>A
public int getNSplitter() |lY8u~%
{ pUx@QyrI
return nSplitter; AWcPOU
} F$C:4c
C%"@|01cO
,3u19>2
public void setNSplitter(int nCount) a8TE
{ S)?B I
nSplitter = nCount; m`aUz}Y>c
} u"ow?[E
} )DMbO"7
3{z }[@N
_qfdk@@g
/* =6:Iv"<
**Utility.java H]\H'r"
*/ LBR_Q0EP
package NetFox; 5E}i<}sq5
5/<Y,eZ/
;H.r6
public class Utility { `SWK(='
^+&}:9Ml
S7R^%Wck/6
public Utility() WObfHAp.
{ .H"gH-I
x($1pAE
gV0ZZ"M
} Ff30%
N]~q@x;<)3
//线程睡眠 fpUX @b
public static void sleep(int nSecond) "]% L{aP
{ j*nCIxF
try{ ^z1WPI
Thread.sleep(nSecond); APya&TG
} Bvwk6NBN
catch(Exception e) 3.Qwn.
{ m`t7-kiZ
e.printStackTrace (); I|hG"i
} =`")\?z}
} 42~;/4
@ggM5mm
//日志 F6Ixu_s
public static void log(String sMsg) .u)YZN0\
{ 5UqCRz<,R
System.err.println(sMsg); Z|.. hZG
} y g7z?AZ
(1R,
99x]DY
public static void log(int sMsg) <K~#@.^`
{ |<S9nZg%p
System.err.println(sMsg); *|cvx:GO
} pn)5neX{
} Sc(2c.HO*
mGX;JOjZ
59LIK&w
/* &'Ch[Wo]H
**TestMethod.java h$3Y,-4
*/ ~lMsD~$sO
package NetFox; rYT3oqpfT
{=kA8U
ITTC}
public class TestMethod { v^pE=f*/
L/shF}<
+] uY
public TestMethod() a)xN(xp##
{ ///xx/weblogic60b2_win.exe ,PnEDQ|l
try{ {.sF&(e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8d]= +n!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SU:Cm:$
SiteFileFetch fileFetch = new SiteFileFetch(bean); .w`8_v&Y
fileFetch.start(); J{91 t |
} 2>mDT
catch(Exception e){e.printStackTrace ();} = hpX2/]
+`ZcYLg)#
){/y-ixH
} WW&0FugY_
~k&b3-A}
x;N?'"GP
public static void main(String[] args) N$.''D?7D
{ edch'H^2+P
new TestMethod(); n'&WIf3
} joa$Y6
} h/X),aK3
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