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)); &5z9C=]e
} 6X?:mn'%QF
for(int i=0;i<nEndPos.length-1;i++) H8HVmfM
{ ?UOaqcL
nEndPos = nStartPos[i+1]; /`nkz
} ]sE)-8
nEndPos[nEndPos.length-1] = nFileLength; piuM#+Y\'S
} H!OX1F
} & BY\h:
%4V$')rek
kt\,$.v8
//启动子线程 261? 8&c
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Oo FMOlb.Z
for(int i=0;i<nStartPos.length;i++) q4G$I?4
{ XZ3fWcw[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6%:~.ZfN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'Nuy/\[{\
nStartPos,nEndPos,i); P{:Zxli0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2mMi=pv9
fileSplitterFetch.start(); ,=c(P9}^
} 1CSGG'J]E
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]\oT({$6B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {.[EXMX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", G-K{
nEndPos = " + nFileLength); mh`uvqY
// fileSplitterFetch[nPos.length-1].start(); ur=:Ha
zxH<~2
0 z]H=
//等待子线程结束 JP5en
//int count = 0; _8F;-7Sz
//是否结束while循环 R$A%Zh6
boolean breakWhile = false; W=LJhCpRHj
|!7leL
=1(7T.t
while(!bStop) suW|hh1/Ya
{ :F#^Q%-IS
write_nPos(); 7#oq|5
Utility.sleep(500); 3/uvw>$
breakWhile = true; LHu
ja/wI'J<
8faT@J'e;
for(int i=0;i<nStartPos.length;i++) $<C",&
{ !<VP[%2L~
if(!fileSplitterFetch.bDownOver) 2Ub-ufkU
{ Li0+%ijM
breakWhile = false; l{ql'm
break; 98^7pa
} j6$@vA)
} _3wK: T{:
if(breakWhile) i+< v7?:`#
break; T<b*=i
/vi Ic %=
~Cw7.NA{3
//count++; A{k1MA<F6
//if(count>4) < 3*q) VT
// siteStop(); NjA[(8\:
} UJ%.KU%Q}
f8=qnY2j
G(Hr*T%
System.err.println("文件下载结束！"); v.vkQQ0[9
} +ZiYl[_|
catch(Exception e){e.printStackTrace ();} m .(\u?J
} m_Z(osoE#W
u^c/1H:6
)Y'g;
//获得文件长度 Ui9;rh$1eU
public long getFileSize() eT5IL(mH
{ H\E%.QIx
int nFileLength = -1; ?"<m{,yQI
try{ C.LAr~P
URL url = new URL(siteInfoBean.getSSiteURL()); M5dEZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -MsL>F.]
httpConnection.setRequestProperty("User-Agent","NetFox"); Qt_KUtD
ad47 42
NV?XZ[<*<
int responseCode=httpConnection.getResponseCode(); -)Vy)hD,
if(responseCode>=400) ZqpK}I
{ c=bK_Z_
processErrorCode(responseCode); V>E7!LIn.
return -2; //-2 represent access is error c&wiTvRV
} Nge@8
C?]eFKS."
#.fJ M:"tG
String sHeader; _s5FYb#
#Cy3x-!
)+8r$ i
for(int i=1;;i++) +|8.ymvm
{ ZG#:3d*)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Vkd_&z7
//Utility.log(in.readLine()); c9Cc%EK
sHeader=httpConnection.getHeaderFieldKey(i); xx7&y!_
if(sHeader!=null) k$8Zg*)
{ YO?o$Hv16
if(sHeader.equals("Content-Length")) :sLg$OF
{ x>BFK@#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )b=vBs`%
break; K7(k_4
} >hq{:m
} Y"KJ`Rx
else &b*v7c=o
break; 4${3e Sg_
} _5(p=Zc
} wL>*WLfR
catch(IOException e){e.printStackTrace ();} #2:?N8vz*
catch(Exception e){e.printStackTrace ();} #Z `Tk)u/
5WxNH}{
iyr8*L\
Utility.log(nFileLength); 99By.+~pX
)\2KDXc
/38I(0
return nFileLength; V lO^0r^z
} FV aC8Kw
QHUFS{G]
3&{6+A
//保存下载信息（文件指针位置） 'W54 T
private void write_nPos() Fs=x+8'M
{ vkR~nIp
try{ !Y7$cU &
output = new DataOutputStream(new FileOutputStream(tmpFile)); y!R9)=/M
output.writeInt(nStartPos.length); 4MW oGV9
for(int i=0;i<nStartPos.length;i++) fl9VokAT
{ \+Y=}P>
// output.writeLong(nPos); ;pOV; q3j
output.writeLong(fileSplitterFetch.nStartPos); KD+&5=Y
output.writeLong(fileSplitterFetch.nEndPos); Bj><0 cNF
} Iw( wT_
output.close(); b2[U3)|oO
} #DJZ42
catch(IOException e){e.printStackTrace ();} T3"'`Sd9;
catch(Exception e){e.printStackTrace ();} F:jtzy"
} 9xw"NcL
%Ny1H/@Q1+
H_x}-
//读取保存的下载信息（文件指针位置） V:P]Ved
private void read_nPos() ;qbK[3.
{ "zTy_0[;
try{ [P ;fv
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f2SJ4"X
int nCount = input.readInt(); 4@<wN \'
nStartPos = new long[nCount]; xE!0p EHd
nEndPos = new long[nCount]; +\&6Zbn
for(int i=0;i<nStartPos.length;i++) ~=[5X,Ta
{ U#iW1jPE2
nStartPos = input.readLong(); @]2aPs} }6
nEndPos = input.readLong(); 'o0o.&/=
} yIngenr$
input.close(); xSlgq|8
} 2|B@s3a
catch(IOException e){e.printStackTrace ();} /%p ~
catch(Exception e){e.printStackTrace ();} }''0N1,/
} Lpkx$QZ
$XMpC{
a$^)~2U{
private void processErrorCode(int nErrorCode) Pw7uxN`
{ P,WQN[(+
System.err.println("Error Code : " + nErrorCode); <}8G1<QZ'.
} S0:Oep
k&f/f
$E^sA|KcT
//停止文件下载 ,%xat`d3,3
public void siteStop() N2[jBy8M
{ bDh4p]lm
bStop = true; C Q iHk
for(int i=0;i<nStartPos.length;i++) UukY9n];]
fileSplitterFetch.splitterStop(); noa+h<vGb
7SYe:^Dx
2h*aWBLk
} )T gfd5B
} 7p':a)
//负责部分文件的抓取 . a @7
**FileSplitterFetch.java mSu$1m8
*/ *& );-r`.
package NetFox; Sw-2vnSdM
Z>Rshtg
<6+B;brh
import java.io.*; *9=}f;~
import java.net.*; CW8YNJ'
AU%Yr6
5? Y(FhnIC
public class FileSplitterFetch extends Thread { /@&o%I3h
:]Om4Q\-#
=B;qy7?
String sURL; //File URL P~:^bU^F7
long nStartPos; //File Snippet Start Position z~p!7q&g
long nEndPos; //File Snippet End Position 7^! zT
int nThreadID; //Thread's ID Xg_l4!T_l
boolean bDownOver = false; //Downing is over iY2q^z/S
boolean bStop = false; //Stop identical q^wSM
FileAccessI fileAccessI = null; //File Access interface Hi~)C\
G^K;+&T
4Jc~I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Bt$,=k
{ _<c}iZv@
this.sURL = sURL; .:Wp9M
this.nStartPos = nStart; `<<9A\Y-f
this.nEndPos = nEnd; >>C S8
nThreadID = id; zlQBBm;fE
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3%o}3.P,:@
} Lp|n)29+du
y,n.(?!*
xpuTh"ED
public void run() eA?|X|
{ T7/DH
while(nStartPos < nEndPos && !bStop) eA Fp<2g
{ x]%,?Vd?
Gkfzb>_V]
~/aCzx~
try{ j)iUg03>/4
URL url = new URL(sURL); \/Q~C!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M($GZ~ b%A
httpConnection.setRequestProperty("User-Agent","NetFox"); v6uRzFw
String sProperty = "bytes="+nStartPos+"-"; 0ZI}eZA j
httpConnection.setRequestProperty("RANGE",sProperty); y>u|3:z
Utility.log(sProperty); 7!Im|7Ty
ttlMZLX{TJ
Y@MxKKuj
InputStream input = httpConnection.getInputStream(); UM21Cfqex
//logResponseHead(httpConnection); kqo4 v;r
:2vuc!Pu
i7YUyU
byte[] b = new byte[1024]; OR|Jc+LT
int nRead; b~)2`l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E|_8#xvb
{ c`lL&*]
nStartPos += fileAccessI.write(b,0,nRead); z}$.A9yn
//if(nThreadID == 1) [GI2%uA0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sVmqx^-
} -*T0Cl.
KZAF9
ta x:9j|~
Utility.log("Thread " + nThreadID + " is over!"); Lrr(7cH,
bDownOver = true; eIlovq/X
//nPos = fileAccessI.write (b,0,nRead); LZs'hA<L
} oGg<s3;UND
catch(Exception e){e.printStackTrace ();} ]EDCs?,
} L 9cXgd
} mC0Dj O
i=P}i8,^=
THK^u+~LM
//打印回应的头信息 w&VDe(:~
public void logResponseHead(HttpURLConnection con) TPKD'@:x
{ (./Iq#@S
for(int i=1;;i++) 8+Gwv SDU
{ >T0`( #Lm
String header=con.getHeaderFieldKey(i); #(+V&<K
if(header!=null) z_{_wAuY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fF9hL3h?)
Utility.log(header+" : "+con.getHeaderField(header)); Vl<7>
else ~P~q'
break; OmfHrlA
} S-7C'dc
} pbWjTI$
c_.Fe'E
i?eVi
public void splitterStop() %hH> %
{ Up_"qD6
bStop = true; T;PLUjp}
} -'*<;]P+.
}:J-o
"K+EZ%~<
} \&Bdi6xAy
9GTp};Kg
3%Q9521
/* #@1(
**FileAccess.java 4HGS
*//文件访问(定位，写) STg} Z
package NetFox; "i*gJFW|
import java.io.*; V(io!8,
itc\wn
%S$$*|_G
public class FileAccessI implements Serializable{ })J}7@VPO
#Oq.}x?i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |*-<G3@
RandomAccessFile oSavedFile; <viC~=k;
long nPos; >XM]UdP
:Y9/} b{
IAe/)
public FileAccessI() throws IOException qss)5a/x.
{ $ye>;Ek
this("",0); x_C0=Q|K3
} d:#tN4y7(
cJTwgm?
tL<.B
public FileAccessI(String sName,long nPos) throws IOException w $`w
{ ^7=7V0>,:
oSavedFile = new RandomAccessFile(sName,"rw"); '^$+G0jv
this.nPos = nPos; WA:r4V
oSavedFile.seek(nPos); KU]o=\ak%
} P46Q3EE
?gjx7TQ?
v#X#F9C
public synchronized int write(byte[] b,int nStart,int nLen) .`v%9-5v
{ ja&m-CFK
int n = -1; E'SDT*EI
try{ "J+4
oSavedFile.write(b,nStart,nLen); %so{'rQl
n = nLen; ?0+g.,9
} e:C4f
catch(IOException e) nf1 `)tXG
{ 0!$y]Gr
e.printStackTrace (); vP? T
} @_#\qGY
n}(A4^=4KQ
K1]3zLnS
return n; *-Vr=e<8
} %yk_(3a
o[+t}hC[
wArfnB&
} 6f ?,v5
Vry_X2
HSAr6h
/* 6h %rt]g
**SiteInfoBean.java wp> z04
*/ $b53~
package NetFox; r`h".=oD
~<s^HP2U{
S'hUh'PZ
public class SiteInfoBean { *yjnC
/4+(eI7
0 ]L
private String sSiteURL; //Site's URL ^M;#x$Y?
private String sFilePath; //Saved File's Path #h4FLF_w
private String sFileName; //Saved File's Name ]6Awd A
private int nSplitter; //Count of Splited Downloading File ZKpJc'h
('Uj|m}9
t*)mX2R,
public SiteInfoBean() VYO1qj
{//nSplitter的缺省值为5 lCl5#L9
//default value of nSplitter is 5 w&Gc#-B
this("","","",5); }N$f=:iI
} EUQtl_h/H
d)acWF\
/!MKijI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &;L=f;
{ ^w<aS w
sSiteURL= sURL; L/] (pXEp
sFilePath = sPath; X ,^([$
sFileName = sName; Pt/]Z<VL
this.nSplitter = nSpiltter; lI.oyR'
uN>5Eh&=Pf
h8(>$A-
} PwthYy
0\B{~1(^
0_MtmmL.
public String getSSiteURL() d%-/U!z?
{ %d(= >
return sSiteURL; 8"ZS|^#
} .5}Gt>4XM
57gt"f
4K? \5(b
public void setSSiteURL(String value) JPng !tvR
{ 8UqH"^9.Q7
sSiteURL = value; xSSEDfq
} tpO'<b
7C,giCYU
y)CvlI
public String getSFilePath() [A"=!e$<
{ GdVF;
return sFilePath; jY]51B
} Gsb^gd
N)R5#JX
*L$_80
public void setSFilePath(String value) " r o'?
{ 1 ptyiy
sFilePath = value; [0]A-#J
} ZILJXX4
"*F`,I3
~QxW^DGa7]
public String getSFileName() B%MdJD>
{ pq&[cA_w
return sFileName; K%x]:|,>M
} IM/xBP
x-X~'p'f
BI%XF 9{
public void setSFileName(String value) #u8#< ,w
{ 9q_{_%G%
sFileName = value; #ye`vD
} ?6`B;_m
kROIVO1|`
{ilz[LM8(
public int getNSplitter() N!3Tg564j
{ z8JW iRn
return nSplitter; F@f4-NR>
} -D'XxOI
Bdb}4X rL
>V27#L2:J
public void setNSplitter(int nCount) AD?XJ3
{ R]&Csr#~
nSplitter = nCount; e(|Z<6
} -bHlFNRm
} /(51\RYkir
'hs4k|B
PS+~JwDUc
/* 4YikC
**Utility.java 4\ Xaou2V[
*/ -$[&{.B.
package NetFox; 1Z @sh>X|
s_VcC_A
9*ZlNZ
public class Utility { >$L7J=Em
2tpuv(H;
^4^N}7>5
public Utility() Q+9:]Bt
{ ".(vR7u'
D_czUM
\WE&5 9G
} ~U"m"zpLP
&s vg<UZ
//线程睡眠 bHv"!
public static void sleep(int nSecond) ?{B5gaU9F
{ p8%qU>~+4
try{ n-"(~
Thread.sleep(nSecond); ka\{?:r,8
} W3/bM>1
catch(Exception e) $KGMAg/H
{ dVEs^ZtI
e.printStackTrace (); eDZ8F^0
} \?T9v
} zHX\h[0f
Jl`^`Yv
//日志 =zK4jiM1
public static void log(String sMsg) 4hwb] Yz
{ J#F5by%8
System.err.println(sMsg); *0!p_Hco
} Hf]:mhH
9AX}V6\+
n2B%}LLa
public static void log(int sMsg) 1?FG3X 5
{ DMG~56cTO,
System.err.println(sMsg); /ta}12Z
} A%W]XEa<
} )PP yJ@M
8e*skL
K%\r[NF
/* yT@Aj;X0v
**TestMethod.java h' !C
*/ ?0qD(cfx<
package NetFox; pS ](Emn`.
:)lG}c
|di(hY|
public class TestMethod { S=!WFKcJR
<7\j\`
i3N{Dt
public TestMethod() 3u/JcU-<
{ ///xx/weblogic60b2_win.exe [StnKQ?"wz
try{ HdqB B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K_)~&Cu*'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qsep9z.
SiteFileFetch fileFetch = new SiteFileFetch(bean); VRQ`-#
fileFetch.start(); c.IUqin
} znsQ/[
catch(Exception e){e.printStackTrace ();} w8:[w
%%s)D4sW
9efey? z
} S9Yzvq!(
3d6z_Yd:
ITw *m3
public static void main(String[] args) W<X3!zuKSg
{ $kTm"I
new TestMethod(); x:MwM?
} s"=TM$Vb
} 8c)GUx
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