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)); F'fM?!(
} yFa&GxSq
for(int i=0;i<nEndPos.length-1;i++) ;Ce 2d+K
{ _6| /P7"
nEndPos = nStartPos[i+1]; s-y'<(ll
} z, :+Oc
nEndPos[nEndPos.length-1] = nFileLength; $d5&~I
} ]q@rGD85K
} 7?)m(CFy
H74NU_
N7%=K9
//启动子线程 &Qz"nCvJ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 48W:4B'l9
for(int i=0;i<nStartPos.length;i++) _zAc 5rS
{ Uia)5zz8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t^dakL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &fh.w]\
nStartPos,nEndPos,i); K1CMLX]m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sz){uOI
fileSplitterFetch.start(); q|m#IVc
} 0R.Gjz*Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z2$FYn Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); zkw0jX~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", tVK?VNW
nEndPos = " + nFileLength); !hpTyO+%
// fileSplitterFetch[nPos.length-1].start(); _AA`R`p;
2-/YYe;C
0^_)OsFA
//等待子线程结束 m mw)C"
//int count = 0; t(Cq(.u`:
//是否结束while循环 \v B9fA:*
boolean breakWhile = false; \["1N-q b
fte!Ll'
\L&qfMjW"Z
while(!bStop) ZfF`kD\
{ rl_1),J\qG
write_nPos(); +X4ttv
Utility.sleep(500); #0#V$AA>
breakWhile = true; .oB'ttF1
y$"~^8"z
C:TuC5Sr
for(int i=0;i<nStartPos.length;i++) jp\JwE
{ oQKcGUZ
if(!fileSplitterFetch.bDownOver) [7CH(o1a&
{ j.e`ip
breakWhile = false; s7X~OF(#
break; K[Ws/yc^a
} oc,U4+T
} (W{rv6cq
if(breakWhile) j8F~j?%!
break; u/K)y:ZZ
ueS[sN!
cviN$oL
//count++; '{1W)X
//if(count>4) gGceK^#
// siteStop(); 1yY'hb,0
} QB oZCLv
d60Fi#3d
a93d'ZE-X
System.err.println("文件下载结束！"); 0VWCm( f-
} C=pPI
catch(Exception e){e.printStackTrace ();} ^.B `Z{Jb
} ()rx>?x5
rA&#>R`
n[S41809<
//获得文件长度 ^y;OHo
public long getFileSize() z;Gbqr?{{
{ 7m@^=w
int nFileLength = -1; Z"PDOwj5
try{ |M0,%~Kt
URL url = new URL(siteInfoBean.getSSiteURL()); h)aWerzL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D[FfJcV'$
httpConnection.setRequestProperty("User-Agent","NetFox"); A,A-5l<h]?
EIVQu~,H
Q?I"J$]&L
int responseCode=httpConnection.getResponseCode(); 8Y;zs7Y
if(responseCode>=400) QL|:(QM
{ E|6Z]6[
processErrorCode(responseCode); kcZ;SYosj
return -2; //-2 represent access is error -qnXa
} 71.:p,Z@z
<o"D/<XnB3
kAKqW7,q"
String sHeader; eUUD|U*b
j)SgB7Q
au9Wo<mR
for(int i=1;;i++) D aqy+:
{ f T+n-B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Wy0a2Ve
//Utility.log(in.readLine()); 1V?Sj
sHeader=httpConnection.getHeaderFieldKey(i); 6DiA2'{f
if(sHeader!=null) D2wgSrY
{ `'tw5}
if(sHeader.equals("Content-Length")) D;#Yn M3
{ R'a5,zEo/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F.* snF
break; (J) Rs`_
} ezNE9g
} xF:poi
else zI*/u)48
break; K]=>F
} wW)&Px n
} `peJ s~V
catch(IOException e){e.printStackTrace ();} IUBps0.T\
catch(Exception e){e.printStackTrace ();} wx?{|
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v!v0,?b*
Utility.log(nFileLength); B}xo|:f!zj
{Z{NH:^
qh'f,#dI}
return nFileLength; 7{/:,
} rF j)5~
'<E8<bi
Xrzh*sp
//保存下载信息（文件指针位置） F|ML$
private void write_nPos() S:GUR6g8D
{ C?c-V,
try{ p?gLW/n
output = new DataOutputStream(new FileOutputStream(tmpFile)); MBTt'6M
output.writeInt(nStartPos.length); Exo`Z`m`U
for(int i=0;i<nStartPos.length;i++) =[-- Hf
{ R`3>0LrC8
// output.writeLong(nPos); Wg;TXs/
output.writeLong(fileSplitterFetch.nStartPos); $vicHuX!
output.writeLong(fileSplitterFetch.nEndPos); PQI,vr'R
} +cOI`4`$
output.close(); eVK<%r=
} <OO/Tn'a
catch(IOException e){e.printStackTrace ();} oG_'<5Bv>
catch(Exception e){e.printStackTrace ();} $@f3=NJ4k
} rp[oH=&
UDi3dH=
rM?Dp2
//读取保存的下载信息（文件指针位置） ,/?V+3l
private void read_nPos() aFm]?75
{ d4eCBqx
try{ rL+n$p X-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7 V1k$S(
int nCount = input.readInt(); Vv"wf;#
nStartPos = new long[nCount]; I4p= ?Ds
nEndPos = new long[nCount]; _e@qv;*
for(int i=0;i<nStartPos.length;i++) F'_8pD7
{ <rI$"=7
nStartPos = input.readLong(); %T*+t"\)
nEndPos = input.readLong(); pvdZ>D-IU
} HG6{`i
input.close(); [/,6O
} Rw^YTv
catch(IOException e){e.printStackTrace ();} jN[6JY1
catch(Exception e){e.printStackTrace ();} g~["O!K3
} 9@EnmtR
:/[ZgreN6
J?ZVzKTb>}
private void processErrorCode(int nErrorCode) Pds*M?&F
{ 4qXUk:C@m
System.err.println("Error Code : " + nErrorCode); 8ch~UBq/
} `1v!sSR0R
$aI MQ[(
\gQ+@O&+
//停止文件下载 S<9d^= a
public void siteStop() fQA)r
{ umrI4.1c
bStop = true; 2o5<nGn
for(int i=0;i<nStartPos.length;i++) ?4?jG3p
fileSplitterFetch.splitterStop(); PC7.+;1
B148wh#r
BW\5RIWwE5
} .W.U:C1
} 67:<X(u+!
//负责部分文件的抓取 !Jp.3,\?~
**FileSplitterFetch.java #UN{ J6{
*/ 2EcYO$R!
package NetFox; +VCo=oA
D>^ix[:J
Sqt"G6<
import java.io.*; 3E@&wpj
import java.net.*; 3Qr!?=nf
&rWJg6/
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public class FileSplitterFetch extends Thread { l"!;Vkg.5
<RsKV$Je I
3n)iTSU3
String sURL; //File URL E1v<-UPbA
long nStartPos; //File Snippet Start Position =w?cp}HW
long nEndPos; //File Snippet End Position g]Ny?61
int nThreadID; //Thread's ID H)fo4N4ii
boolean bDownOver = false; //Downing is over )_.H #|r
boolean bStop = false; //Stop identical O5*uL{pvT{
FileAccessI fileAccessI = null; //File Access interface =YsTF T
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54j $A
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6oBt<r?CJ
{ <aD+Ki6
this.sURL = sURL; `7n,(
this.nStartPos = nStart; u"|nu!p`
this.nEndPos = nEnd; `8bp6}OD,
nThreadID = id; xEWa<P#.u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /7)G"qG~F~
} 7+-}8&syu
Rp9iX~A`e
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public void run() sgsMlZ3/
{ <W^~Y31:0
while(nStartPos < nEndPos && !bStop) KePHn:c
{ 0].5[Jo
'Em($A(
Di=6.gm[<
try{ O]!DNN
URL url = new URL(sURL); DcDGrRuh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gukq}ZQd
httpConnection.setRequestProperty("User-Agent","NetFox"); %LW~oI.
String sProperty = "bytes="+nStartPos+"-"; ? D'-{/<4
httpConnection.setRequestProperty("RANGE",sProperty); V-u\TiL
Utility.log(sProperty); 4f-C]N=
@"2-tn@q_
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InputStream input = httpConnection.getInputStream(); 9K(b Z{
//logResponseHead(httpConnection); Q:|E
emO!6]0gJ
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byte[] b = new byte[1024]; _{);n$`
int nRead; P=z':4,M}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j* ?MFvwE
{ [_Z3v,vt,
nStartPos += fileAccessI.write(b,0,nRead); <[~M|OL9q,
//if(nThreadID == 1) IrM3Uh
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kS!*kk*a
} % m$Mnx
PrxXL/6
0CYI,V
Utility.log("Thread " + nThreadID + " is over!"); $OuA<-
bDownOver = true; O-YE6u
//nPos = fileAccessI.write (b,0,nRead); @#">~P|Hp
} XA%?35v~
catch(Exception e){e.printStackTrace ();} !4fL|0
} YJ`>&AJ
} ?-i&6i6Y
pqX=l%{4ES
p]HtJt|]
//打印回应的头信息 7n.J.<+9
public void logResponseHead(HttpURLConnection con) <C(2(3
{ ,)8Hl[y
for(int i=1;;i++) >MLqOUr#
{ ~Q\[b%>J
String header=con.getHeaderFieldKey(i); Hqv(X=6E0
if(header!=null) Pr'py
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 35et+9
Utility.log(header+" : "+con.getHeaderField(header)); =*N(8j>y
else <#i'3TUR
break; F"I@=R-n
} WX9BS$}0
} SY.V_O$l}
5O*$#C;c
6A<aelE*i
public void splitterStop() Zs)9OJu
{ +q!6zGs.
bStop = true; B{<6&bQ
} K+H82$ #
`. Z".
lC{m;V2
} Wit1WI;18
Pc-HQU
A,@"(3
/* /);6 j,x
**FileAccess.java x8t1g,QA
*//文件访问(定位，写) ,;;~dfHm
package NetFox; &kGSxYDk%
import java.io.*; Px`yD3
4l:+>U@KU
w@R-@ G
public class FileAccessI implements Serializable{ W%x#ps5%
O4{&B@!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O1PdM52
RandomAccessFile oSavedFile; "wc $'7M
long nPos; Z]dc%>
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[iz
public FileAccessI() throws IOException E2l.
{ 08Gr
this("",0); ?Z"}RMM)8
} wlJ_,wA
1Y_fX
AkF3F^
public FileAccessI(String sName,long nPos) throws IOException *niQ*A
{ 5 ,HNb
oSavedFile = new RandomAccessFile(sName,"rw"); YN^8s
this.nPos = nPos; j"]%6RwM]
oSavedFile.seek(nPos); V=U%P[S
} Aka`L:k
/TdTo@
#frhO;6
public synchronized int write(byte[] b,int nStart,int nLen) Wp ]u0w
{ UA^E^$f:
int n = -1; 7G(X:!
try{ +!rK4[W'
oSavedFile.write(b,nStart,nLen); Nz8iU@!a
n = nLen; se-}d.PwL
} 6%>0g^`)9Y
catch(IOException e) }[|"db
{ BdSTB"
e.printStackTrace (); p<YO3@B+
} tSjK=1"}
3N-(`[m{E
6 J#C
return n; yq2Bz7P
} Nt)9-\T
D6D*RTi4
%(i(ZW "
} AdhCC13B
IkupW|}rc
x&sF_<[
/* ({)_[dJ'
**SiteInfoBean.java q /#O :Q
*/ $O[ut.
package NetFox; (%bfNs|
1BF+sT3
0kDT:3
public class SiteInfoBean { S5;q)qz2J
db`<E <
mJ-@:5
private String sSiteURL; //Site's URL {Su]P {oJ
private String sFilePath; //Saved File's Path $iV3>>;eh
private String sFileName; //Saved File's Name ;^;5"nh
private int nSplitter; //Count of Splited Downloading File Zhw _L
d(&vIjy
T]+*}C
public SiteInfoBean() 6;VlX,,j
{//nSplitter的缺省值为5 :=* -x
//default value of nSplitter is 5 V[%r5!83H
this("","","",5); 0pu'K)Rb
} :]x)lP(3E
dX<UruPA
^b4o 0me
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;@sxE}`?g
{ Wd[XQZ<
sSiteURL= sURL; CNzK-,
sFilePath = sPath; #SL/Jr DZ
sFileName = sName; 4;_.|!LN
this.nSplitter = nSpiltter; Q)v8hNyUmA
]O 2_&cs
2)G ZU
} X;-,3dy
Z:'2puU+?
d(k`Yk8
public String getSSiteURL() i+2J\.~U#G
{ m^`X|xK-
return sSiteURL; b*,R9
} Ros5]5=dP
:yv! x
1r@v \#P
public void setSSiteURL(String value) }3@`'i7
{ 0<e7!M=U1
sSiteURL = value; [QeKT8
} "5{\0CfS
4((Z8@iX/
9~N7hLT
public String getSFilePath() %e_WO,R
{ ImgKqp0Z
return sFilePath; (|Xf=q,Le
} &%^[2^H8"
z8A`BVqI
l.C{Ar
public void setSFilePath(String value) Yd]f}5F
{ -5.>9+W8I
sFilePath = value; `9@!"p f
} Q&wBX%@^L
18a6i^7
Xa-]+_?Q
public String getSFileName() u6I# D _
{ YV0e)bf
return sFileName; _oR6^#5#
} jk)U~KGcg
(RGl, x:
wjpkh~qo
public void setSFileName(String value) LM0TSB?
{ i^j{l_-JE
sFileName = value; d@`yRueWiV
} =_=jXWOQv
F*}b),
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public int getNSplitter() AX[/S8|6
{ c,x2
return nSplitter; \}Hk`n)Aq
} @@}A\wA-
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YAsvw\iseK
public void setNSplitter(int nCount) J0^p\mG
{ D,]m7yFT
nSplitter = nCount; 2N`Vx3
} -0lpsF
} 3vDV
=T;%R^@
,X+071.(
/* OpYq qBf_
**Utility.java )6Z)z;n]aW
*/ >KC*xa"
package NetFox; ("wPkm^
E/Y.f
ePB=aCZ
public class Utility { ;v#~o*
lAV6z%MmM
0G;RMR':5
public Utility() R>#T{<<L
{ +n1}({7m
%5jxq9:K
,odjL6u
} w~Es,@
N(/DC)DJg
//线程睡眠 QfRt3\^`
public static void sleep(int nSecond) oQFpIX;\m
{ UP%X`
try{ '^}l|(
Thread.sleep(nSecond); dAohj QH:
} '0z@Jevd?
catch(Exception e) 2~~Q NWN
{ 866n{lyL
e.printStackTrace (); Z6 (;~"Em
} kQwBrb4
} L)4TW6IUk
T<?JL.8g_
//日志 qzsS"=5
public static void log(String sMsg) "P'W@
{ EivZI<<a
System.err.println(sMsg); tb^3-ZUb
} A1>R8Zuhy
_D[vMr[
Sh}AGNE'
public static void log(int sMsg) cPkN)+K
{ !~"q$T>@
System.err.println(sMsg); $yHlkd`Y
} 2U)H2%
} "PLZZL$+
R/A40i
gfFP-J3cN
/* 7YkxIzE
**TestMethod.java 6*{N{]`WZ)
*/ N@)tU;U3O
package NetFox; V<?t(_Y
_Z@- q
r8}GiP0|
public class TestMethod { RWz^ MV5K
*GTCVxu
[D^KM|I%+
public TestMethod() (KK9/k
{ ///xx/weblogic60b2_win.exe 7P.C~,+D%P
try{ YSs9BF:a
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); iKs/8n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V2V^*9(wu@
SiteFileFetch fileFetch = new SiteFileFetch(bean); XW%!#S&;X
fileFetch.start(); ccZ A
} t%/Y^N;
catch(Exception e){e.printStackTrace ();} G<Z|NT
`$fwLC3j
<pK72
} Ti=~ycwi
KaZ$!JfT
m("! M~1
public static void main(String[] args) d/j$_NQ&!
{ Yq $(Ex
new TestMethod(); .UU BAyjm
} F]q pDv
} ezY _7
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