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)); &aOOG8l
} Y$^QH.h
for(int i=0;i<nEndPos.length-1;i++) q?\D9aT9
{ HC+R:Dz
nEndPos = nStartPos[i+1]; 10^=1@U
} /-lmfpT
nEndPos[nEndPos.length-1] = nFileLength; 2F(j=uV+
} v/dcb%
} *<1m 2t>.
UHWunI S
d8po`J#nb
//启动子线程 =t2epIr5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; NKws;/u
for(int i=0;i<nStartPos.length;i++) ImVe71mh
{ ^;d;b<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /_8V+@im
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G39t'^ZK*#
nStartPos,nEndPos,i); v\vn}/>*d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I%Z&i-33y
fileSplitterFetch.start(); b`mEnI VIz
} Tj:F Qnx
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vvCGzOv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JAK*HA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zZ63 P
nEndPos = " + nFileLength); T5)?6i-N
// fileSplitterFetch[nPos.length-1].start(); dWA7U6c<
AXFVsZH"zi
m" GrpE3
//等待子线程结束 :&MiO3#+
//int count = 0; 04:Dbt~=?p
//是否结束while循环 4Ki'r&L\
boolean breakWhile = false; L<n_}ucA
Cpl)byb
qI}Zg)q]
while(!bStop) -_+0[Nb.
{ 6822xk
write_nPos(); y-YYDEl
Utility.sleep(500); sQw-#f7t
breakWhile = true; Sk-Ti\
E_P]f%
(_2eiE71
for(int i=0;i<nStartPos.length;i++) l:+1j{ d7
{ Up:#Zs2
if(!fileSplitterFetch.bDownOver) = j -
{ "q8wEu,z[
breakWhile = false; [}D)73h`
break; eYFCf;
} &oBJY'1
} N~Gh>{N
if(breakWhile) EifYK
break; jp|wc,]!
^H'#*b0u
K^+B"
//count++; {ib`mC^
//if(count>4) _B2t|uQ
// siteStop(); Wo&i)S<i0F
} %zGPF
h!MT5B)r.
ETtR*5Y 5
System.err.println("文件下载结束！"); =S,^"D\Z:
} |zf||ju
catch(Exception e){e.printStackTrace ();} b\?`721BG
} :}lE@Y,R
q:(K^
lWR
//获得文件长度 S}<(9@]z
public long getFileSize() Q]\xO/
{ 'EQAG' YV
int nFileLength = -1; =vWnqF:
try{ =~)n,5
URL url = new URL(siteInfoBean.getSSiteURL()); 2 UgjH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |Z<adOg
httpConnection.setRequestProperty("User-Agent","NetFox"); *+G K?Ga
V}("8L
S9.jc@#.`
int responseCode=httpConnection.getResponseCode(); 7W*OyH^
if(responseCode>=400) (L\tp> E-
{ D4G{= Y}G
processErrorCode(responseCode); C9fJLCufC
return -2; //-2 represent access is error -`( :L[
} nv={.H
JO$0Z
X@ss d
String sHeader; *m;L.r`5[
eu~;G H
wZ\0<skU
for(int i=1;;i++) 0Bll6Rd
{ $]_=B Jyu
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @`T6\ 1
//Utility.log(in.readLine()); 4#o` -vcW
sHeader=httpConnection.getHeaderFieldKey(i); ji1A>jepF
if(sHeader!=null) 7M4iBk4I
{ P++gR@
if(sHeader.equals("Content-Length")) :F_U^pyG
{ te`4*t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); It4F;Ah
break; hk~s1"
} {*: C$"L
} )TxhJB5|
else KS%,N _F<
break; V/03m3!q
} >uVG]
} F$caKWzny5
catch(IOException e){e.printStackTrace ();} __a9}m4i7x
catch(Exception e){e.printStackTrace ();} zUOYH4+
4:K9FqU
-+z^{*\;N
Utility.log(nFileLength); Q5Wb)
]UNmhF!W>u
2Bx\nLf/ K
return nFileLength; Q<M>+U;t
} u}pLO9V"`
4|~o<t8
(|WqOwmoUt
//保存下载信息（文件指针位置） 8.vD]hO
private void write_nPos() ^*ZO@GNL
{ uQ{M<%K
try{ J^u{7K,
output = new DataOutputStream(new FileOutputStream(tmpFile)); H.YntFtD'
output.writeInt(nStartPos.length); #e=[W))
for(int i=0;i<nStartPos.length;i++) $+Xohtt
{ 9Gy1T3y5"
// output.writeLong(nPos); 7,:QFV
output.writeLong(fileSplitterFetch.nStartPos); a^,Xm(Wb}
output.writeLong(fileSplitterFetch.nEndPos); gG#M-2P
} I!{5*~ 3
output.close(); f\Qi()
} Er{yQIi0L
catch(IOException e){e.printStackTrace ();} \KTX{qI"f
catch(Exception e){e.printStackTrace ();} oR5'g7?
} (*#S%4(YX
# TvY*D,
0Rj_l:d=
//读取保存的下载信息（文件指针位置） V-VR+Ndz
private void read_nPos() QqRL>.)W
{ W&*0F~
try{ ZM\Z2L]n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w'}b 8m(L
int nCount = input.readInt(); fi1tF/`
nStartPos = new long[nCount]; $[H3O(B0*
nEndPos = new long[nCount]; +"Ka #Z
for(int i=0;i<nStartPos.length;i++) |TkO'QN
{ |A"zxNeS"
nStartPos = input.readLong(); xw`Pq6
nEndPos = input.readLong(); gx3arVa
} <_h
input.close(); "zv?qS
} *S7<QyVh
catch(IOException e){e.printStackTrace ();} p2\@E} z
catch(Exception e){e.printStackTrace ();} aCQAh[T
} "I u3&mc
V4_ZBeWA
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private void processErrorCode(int nErrorCode) wPyfne?~,
{ Y\s@'UoVN
System.err.println("Error Code : " + nErrorCode); <&B)i\j8=b
} !ouJ3Jn
ht)J#Di
[8[g_
//停止文件下载 n{aD4&
public void siteStop() OLTgBXh
{ 'V/+v#V+>
bStop = true; bDK72cQ
for(int i=0;i<nStartPos.length;i++) Rjt]^gb!*
fileSplitterFetch.splitterStop(); TF2'-"2Y
h<JV6h:8
C`Zz\DNG@
} &Yb!j
} O(#DaFJv
//负责部分文件的抓取 icH\(
**FileSplitterFetch.java CKCot
*/ 4"7/+6Z
package NetFox; w6aq/m"'
G?*)0`~W
FbhF45H
import java.io.*; <<4U:
import java.net.*; yJNQO'wcv
=)!sWY:
p%[/ _ -7
public class FileSplitterFetch extends Thread { Y'H|Tk^`
r1ao=N
G*^4+^Vz?
String sURL; //File URL GUSEbIz):
long nStartPos; //File Snippet Start Position H85JMPZ7
long nEndPos; //File Snippet End Position NH~\kV
int nThreadID; //Thread's ID DxoW,GW
boolean bDownOver = false; //Downing is over GKIO@!@[
boolean bStop = false; //Stop identical U4M}E h8
FileAccessI fileAccessI = null; //File Access interface >cJfD9-<h
aYW9C<5
vnc-W3N
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b1\.hi
{ c&X2k\
this.sURL = sURL; mQUI9
this.nStartPos = nStart; 2!QQypQ
this.nEndPos = nEnd; /-s-W<S[
nThreadID = id; Lh\ 1L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m9M#)<@*
} (ZSd7qH"
d;@"Naw
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public void run() O/ybqU\7
{ t\S=u y
while(nStartPos < nEndPos && !bStop) xl>8B/Zmf#
{ 9?]69O
Y].,}}9k
$\Oc]%
try{ #83`T&Xw*
URL url = new URL(sURL); A{|^_1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 17la/7l<
httpConnection.setRequestProperty("User-Agent","NetFox"); ]-g9dV_[>j
String sProperty = "bytes="+nStartPos+"-"; 4 '"C8vw.
httpConnection.setRequestProperty("RANGE",sProperty); (P'{A>aHl0
Utility.log(sProperty); Ui|z#{8&
}ff+RGxLIG
*be"$Q
InputStream input = httpConnection.getInputStream(); \w#)uYK{i_
//logResponseHead(httpConnection); G{CKb{
FNlS)Bs
'-X[T}
byte[] b = new byte[1024]; ?*LVn~y
int nRead; .7BJq?K.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q<[m(]:
{ _59f.FsVR
nStartPos += fileAccessI.write(b,0,nRead); x/NjdK
//if(nThreadID == 1) x4bmV@b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [|&#A;{F#
} G9_7jX*
/Ixv{H)H
f*o+g:]3
Utility.log("Thread " + nThreadID + " is over!"); L _D#
bDownOver = true; z=/&tRe W
//nPos = fileAccessI.write (b,0,nRead); &$yxAqdab
} +9exap27
catch(Exception e){e.printStackTrace ();} }i$ER,hXh
} 45Hbg
} q\Q'9Rl0(
7K5 tBUNQ
`NySTd)\
//打印回应的头信息 V!\'7-[R
public void logResponseHead(HttpURLConnection con) InA=ty]"_U
{ |W*#N8IP
for(int i=1;;i++) zt;aB>jz#
{ mRO@ZY;5
String header=con.getHeaderFieldKey(i); "*<)pnJ
if(header!=null) G,!{Q''w
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P](/5KrK
Utility.log(header+" : "+con.getHeaderField(header)); .no<#l
else ULH<FDot
break; @)XR
} Tm\a%Z`U>
} >=1Aa,_tc
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(}m2}
public void splitterStop() U0=: `G2l
{ qr4.s$VGs*
bStop = true; 1R,SA:L$
} # Rhtaq9
x7GYWK 9
]w0_!Z&
} s}qtM.^W
p~WX\;
"^Vnnb:Z*o
/* ~jJF&*)
**FileAccess.java /%1-tGh
*//文件访问(定位，写) zJ)`snN|
package NetFox; % oJH 6F
import java.io.*; ]TVc 'G;
_1G;!eO
} `Cc-X7
public class FileAccessI implements Serializable{ }Qa
H1c>3c
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;Wgkf_3
RandomAccessFile oSavedFile; MzMVs3w|
long nPos; & LhQr-g
U1Y0G[i)
`m}G{jfk
public FileAccessI() throws IOException Y0yu,
{ ~p?D[]h
this("",0); 3S .2
} L8J] X7
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.=N?;i
public FileAccessI(String sName,long nPos) throws IOException .Zc:$"gDu
{ D@%!|:
oSavedFile = new RandomAccessFile(sName,"rw"); 5(thDZ!
this.nPos = nPos; QtA@p
oSavedFile.seek(nPos); MxOIe|=&
} F9k}zAY\J
4C[kj
2?F?C
public synchronized int write(byte[] b,int nStart,int nLen) Z.`0
{ 4-BrE&2f
int n = -1; rgo!t028^
try{ j-d542"
oSavedFile.write(b,nStart,nLen); P~84#5R1
n = nLen; z))rk vL%
} N)/7j7c~;
catch(IOException e) tzY?LX[3
{ 9a#Y D;-p
e.printStackTrace (); LJA uTg
} 1 F&}e&}c
9"?;H%.
~l('ly
return n; ~7gFddi=i
} X4L@|"ZI
\0K&2'
M< H+$}[
} .pG`/[*a
558!?kx$
sf O{.#5<
/* ]E.\ |I(
**SiteInfoBean.java FE1'MUT_
*/ Y.q$"lm7k
package NetFox; cqaq~
OepQ Z|2
<sn,X0W
public class SiteInfoBean { PZY6 I
X/buz
tkmzOc H
private String sSiteURL; //Site's URL 3e>U(ES
private String sFilePath; //Saved File's Path e~SRGyIww
private String sFileName; //Saved File's Name r)B55;*Fh
private int nSplitter; //Count of Splited Downloading File *TrpW?]Y&
dkW7k^g
..x2
public SiteInfoBean() P'<j<h6
{//nSplitter的缺省值为5 nt@uVwfQ
//default value of nSplitter is 5 N;DE,[:<
this("","","",5); G^Y^)pc]
} )LsUO#%DO
*to#ZMR;!
i*8j|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]f5vk
{ K+d{R=s^
sSiteURL= sURL; (:^YfG~e
sFilePath = sPath; {P3gMv;
sFileName = sName; (Q.tH
this.nSplitter = nSpiltter; sX]gL
K"!U&`T
t qUBl?i
} 8g=];@z
cG(%P$
XtE O)
public String getSSiteURL() {b-SK5%]L
{ nkz<t
return sSiteURL; xVrLoAw
} |WNI[49
F$'po#
KO/#t~
public void setSSiteURL(String value) ^)o]hE|
{ @V&HE:P
sSiteURL = value; _Ea1;dJmq
} $h}w:AV:
gB>AYL%o=
iVo-z#
public String getSFilePath() eep/96G ?
{ )`S5>[6
return sFilePath; L8oqlq( 9
} fl40jo]
8@){\.M
a p(PI?]X
public void setSFilePath(String value) '*EKi
{ >;#rK@*&
sFilePath = value; Y5P9z{X=
} ERIF#EY
WqS$C;]%
rCb$^(w{7
public String getSFileName() (!?%"e
{ 3HNm`b8G4m
return sFileName; i~3\dp
} brK7|&R<
b&]z^_m)
@1qdnU
public void setSFileName(String value) Nfv` )n@
{ OB++5Wd
sFileName = value; i>C%[dk9
} z@~mu
99%R/m
C' WX$!$d
public int getNSplitter() =$T[
{ TH55@1W,[
return nSplitter; ?m9=Me
} ,|]k4F
I,"q:QS+
]VEc9?
public void setNSplitter(int nCount) 9!0-~,o
{ vP_mS 4X
nSplitter = nCount; ^W`RBrJay
} x_<,GE@
} 3JD"* <zs
9yu#G7
5g;mc.Cvt
/* I0;gTpt9
**Utility.java muDOY~.
*/ o)Px d
package NetFox; R?dMM
fJ=(oF=
R%\<al$O
public class Utility { ^f0-w`D
s=1k9
s7\Ee-x)s
public Utility() uz:r'+v
{ x7i,jMR
|h&okR+_,
JUJrtKS
} di]CYLf
b(adM3MP
//线程睡眠 K.Cx 9
public static void sleep(int nSecond) [#AI!-
{ 7\H_9o0$
try{ 1c*:" k
Thread.sleep(nSecond); twt's,dO
} FTzc,6
catch(Exception e) 7f*b5$+r
{ :OqEkh"$#
e.printStackTrace (); +(`.pa z@
} ^* CKx
} i3)7Qa[
|Qpd<L
//日志 g6$\i m
public static void log(String sMsg) hVCxwTg^X
{ LaL{ ^wP
System.err.println(sMsg); rKTc6h:)
} y>cT{)E$
-vh\XO
mR#"ng
public static void log(int sMsg) ]<9o>#3
{ kLXa1^Lq
System.err.println(sMsg); J:IAs:e`
} A6xN6{R!
} 61sEeM
/N")uuv
?\<Kb|Q
/* MRHRa
**TestMethod.java n<eK\w
*/ Z}IuR|=
package NetFox; +O8}twt@
Y$fF"pG?
{+gK\Nz
public class TestMethod { )/z+W[t
%wGQu;re
:>jzL8
public TestMethod() ;0Ih:YY6
{ ///xx/weblogic60b2_win.exe L9l]0C37e
try{ 6kONuG7Yv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ZfS"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y+EwBg)co
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~F;>4q
fileFetch.start(); Smd83W&
} R0nUS<b0
catch(Exception e){e.printStackTrace ();} ,0?3k
qg*xdefQ%
Q.V+s
} l\u5RMS('
3'7X[{uBr
n0uL^{B
public static void main(String[] args) VT;cz6"6b4
{ !F2JT@6
new TestMethod(); kPSi6ci
} >^v,,R8j
} bV*q~@xh
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