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)); gaxM#
} Dkb`_HI
for(int i=0;i<nEndPos.length-1;i++) n.qT7d(
{ \NMqlxp2
nEndPos = nStartPos[i+1]; :4-,Ru1C"
} t#@z_Mn\
nEndPos[nEndPos.length-1] = nFileLength; @C!&lrf3
} .>#O'Z&q9
} 3!\h'5{
$./aKJ1B
Woj5 yr
//启动子线程 (sQXfeMz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =+K?@;?
for(int i=0;i<nStartPos.length;i++) -)^vO*b 0
{ Xp9I3nd|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cfilH"EK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), U]gUGD!5x
nStartPos,nEndPos,i); 4_iA<}>|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7l$ u.[
fileSplitterFetch.start(); 6pSTw\/6
} ~##FW|N)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j`"!G*Vh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hrq% {!Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", De^:9<{jc
nEndPos = " + nFileLength); GC7WRA
// fileSplitterFetch[nPos.length-1].start(); M;Pry3J
o+}k$i!6
+B1&bOb
//等待子线程结束 yc~<h/}#
//int count = 0; p&x!m}!
//是否结束while循环 aVHIU3
boolean breakWhile = false; hHmm(~5gR
vm[*+&\2
|u?VlRt
while(!bStop) fn,hP_
{ ,3 /o7'
write_nPos(); wpYk`Lr
Utility.sleep(500); #:0-t!<0C
breakWhile = true; hXth\e\[{`
-*4*hHmb
{eI'0==
for(int i=0;i<nStartPos.length;i++) nOL.%
{ 3sdL\
if(!fileSplitterFetch.bDownOver) kMurNA=
{ "lw|EpQk`
breakWhile = false; i(;`x
break; =xIZJ8e
} $'3xl2T
} M yHv>
if(breakWhile) aH{)|?
break; M)+pH
rX?ZUw?u&
N4C7I1ihq
//count++; $U]T8;5Q
//if(count>4) KH;~VR8"/
// siteStop(); z``wqK
} ]5S`y{j1
dREY m}1
uB.kkkGZ M
System.err.println("文件下载结束！"); w'(/dr
} `e =IXkt
catch(Exception e){e.printStackTrace ();} B+`4UfB]Z}
} ( ~5M{Xh
)e?&'wa>
\6&Ml]1
//获得文件长度 tj@(0}pi4
public long getFileSize() e9h@G#
{ b^d{$eoH?|
int nFileLength = -1; WqNXE)'
try{ j %gd:-tA
URL url = new URL(siteInfoBean.getSSiteURL()); :Fb>=e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lJu^Bcrv
httpConnection.setRequestProperty("User-Agent","NetFox"); 2r!ltG3}
i)z|= |?
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int responseCode=httpConnection.getResponseCode(); 0Xh_.PF
if(responseCode>=400) <@-O06
{ . |T=T0^
processErrorCode(responseCode); wL?Up>fr
return -2; //-2 represent access is error TR0y4u[
} c,2& -T}
nL:&G'd
S"Cz. bv
String sHeader; _K~h? \u
eTS}-
M@A3+v%K
for(int i=1;;i++) \tI%[g1M
{ uPz+*4+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ! dzgi:
//Utility.log(in.readLine()); (E0
sHeader=httpConnection.getHeaderFieldKey(i); SraZxuPg>
if(sHeader!=null) {]R'U/
{ !'jq.RawP
if(sHeader.equals("Content-Length")) /e'3\,2_
{ (G"'Fb6d
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V^2_]VFj
break; crM5&L9zF
} | ;tH?E
} JnBUW"
else o]e,5]
break; N6y9'LGG`
} jfxNV2[
} K&|h%4O
catch(IOException e){e.printStackTrace ();} G68KoM
catch(Exception e){e.printStackTrace ();} Y_'ERqQ
EU?qLj':
gpV4qDXV
Utility.log(nFileLength); c|Ivet>3
.{1$;K @
y*i&p4Y*
return nFileLength; +lym8n~-O
} buGBqx[
v/`D0g-uX)
*'/,
//保存下载信息（文件指针位置） ?Z#N9Z~\
private void write_nPos() } !m43x/&
{ ^{+ry<rS>
try{ g&Vhu8kNIA
output = new DataOutputStream(new FileOutputStream(tmpFile)); <>] DcA
output.writeInt(nStartPos.length); 8MJJ w;
for(int i=0;i<nStartPos.length;i++) v ccH(T
{ ')uYI;h9
// output.writeLong(nPos); ,-pE/3|(
output.writeLong(fileSplitterFetch.nStartPos); !vSI"$xd
output.writeLong(fileSplitterFetch.nEndPos); 66v,/#K
} 2@|`Ugjptl
output.close(); > G\0Z[<v,
} Qd}n4KF\
catch(IOException e){e.printStackTrace ();} jRK}H*uem
catch(Exception e){e.printStackTrace ();} 0]DOiA
} 0@ `]m
h[ .
dfDjOZSL
//读取保存的下载信息（文件指针位置） Ni_H1G
private void read_nPos() .p#kW:zspA
{ 7H7 Xbi@
try{ ? x%s j
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ZbFD|~[ V
int nCount = input.readInt(); TDh)}Ms
nStartPos = new long[nCount]; MP%#)O6
nEndPos = new long[nCount]; d<m;Q}/l&h
for(int i=0;i<nStartPos.length;i++) VE\L&d2S
{ _H+]G"k/r
nStartPos = input.readLong(); VI! \+A
nEndPos = input.readLong(); <y6`8J7:
} fv;Q*; oC&
input.close(); BZeEZ2"
} 2q?/aw ;Z
catch(IOException e){e.printStackTrace ();} {53FR
catch(Exception e){e.printStackTrace ();} =E-x0sr?
} <5zR-UA>
(XZ[-M7
}+,Q&]>~
private void processErrorCode(int nErrorCode) 49qa
{ 1[egCC\Mo_
System.err.println("Error Code : " + nErrorCode); OM EwGr(
} t^#1=nK
6uRE9h|
ql?w6qFs]
//停止文件下载 }QE.|.fA1
public void siteStop() mR0`wrt
{ a"(Ws]K
bStop = true; )]>t(
for(int i=0;i<nStartPos.length;i++) `m 5\
fileSplitterFetch.splitterStop(); \mb4leg5
rZUTBLZ`j
z~H1f$}
} d?oXz|;H(
} Y.m1d?H 1
//负责部分文件的抓取 =ejcP&-V/
**FileSplitterFetch.java 0:{W t
*/ S'x ]c#
package NetFox; 49FP&NgK
`I7s|9-=
'(K4@[3t
import java.io.*; B>u`%Ry&
import java.net.*; ?V`-z#y7
=Uk#7U"P
(?Ku-k
public class FileSplitterFetch extends Thread { ~<1s[Hu
|gkNhxzB
|q4=*Xq
String sURL; //File URL 7FwtBO
long nStartPos; //File Snippet Start Position cqU6 Y*n
long nEndPos; //File Snippet End Position ?y|&Mz'XJ(
int nThreadID; //Thread's ID Q<>u)%92@
boolean bDownOver = false; //Downing is over t[|rp&xG
boolean bStop = false; //Stop identical aT^ $'_ G
FileAccessI fileAccessI = null; //File Access interface B7Ket8<J
W[jg+|
DN^+"_:TB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException smCACQ$(
{ mxqZj8VuH
this.sURL = sURL; 7sVM[lr<
this.nStartPos = nStart; wPU5L*/*i
this.nEndPos = nEnd; 9DBX.|
nThreadID = id; [Or1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %)i&|AV"
} WD4"ft
W~H`{x%Av>
8 n[(\f:
public void run() A^lm0[3q
{ :U\*4l
while(nStartPos < nEndPos && !bStop) A8ViJ
{ G5hRx@vfrL
D <~UaHfk
'&Ur(axs
try{ f['I4 /o
URL url = new URL(sURL); (6c/)MH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W,8Uu1X =
httpConnection.setRequestProperty("User-Agent","NetFox"); HnPy";{
String sProperty = "bytes="+nStartPos+"-"; B\D)21Ik}%
httpConnection.setRequestProperty("RANGE",sProperty); z*HM_u
Utility.log(sProperty); t7-r YY(
&SIf|IX.
fFEB#l!oUb
InputStream input = httpConnection.getInputStream(); RAa1^Qb
//logResponseHead(httpConnection); OGEe8Z9Jt
&fRz6Hd
[<r.M<3
byte[] b = new byte[1024]; "wH(tk4
int nRead; m p_7$#{l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !0pK8k&MG
{ NJJ=ch
nStartPos += fileAccessI.write(b,0,nRead); g mWwlkf9
//if(nThreadID == 1) _an0G?7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wMgF*
} nh7_ jEX
7r:&%?2:g
AyUw
Utility.log("Thread " + nThreadID + " is over!"); @?s>oSyV
bDownOver = true; OL_#Uu
//nPos = fileAccessI.write (b,0,nRead); }e|cszNRd
} _KloX{a
catch(Exception e){e.printStackTrace ();} {Zw;<1{E
} 6yYjZ<
} 0NSw^dO\
/\Cf*cJ
].Bx"L!B
//打印回应的头信息 {a\! 1~
public void logResponseHead(HttpURLConnection con) &b>&XMIK
{ S/*\j7cj
for(int i=1;;i++) g/l:q&Q<
{ gdSqG2/&
String header=con.getHeaderFieldKey(i); !m))Yp-"H
if(header!=null) a/s5Oit2'X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7f3,czW
Utility.log(header+" : "+con.getHeaderField(header)); &tbAXU5$
else L[:AUe
break; f.j<VKF}
} QSzht$8
} )^P54_2
*[i49X&rd
L1+s0g>
public void splitterStop() [So1`IA6
{ I%:?f{\
bStop = true; 7MZH'nO
} t@R n#(~"
z.(DDj
&'zc2
} kWa5=BW2f
QoUdTIIL
K2Ro0
/* s5G`?/
**FileAccess.java H}_R`S
*//文件访问(定位，写) K0oF=|
package NetFox; &ID! lEd
import java.io.*; o+8H:7,o'
yaG:}=.3
B1FJAKI);
public class FileAccessI implements Serializable{ ZXo;E
$"( 15U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {A< 961
RandomAccessFile oSavedFile; yFeFI@Hp 3
long nPos; u^MRKLn
nC[aEZ7
(x\VGo
public FileAccessI() throws IOException QL7.QG
{ }=\?]9`
this("",0); o_b3G
} ?[.8A/:5
1MO-60
Xm|~1 k_3
public FileAccessI(String sName,long nPos) throws IOException 'wYIJK~1
{ tw.GBR
oSavedFile = new RandomAccessFile(sName,"rw"); k18v{)i~
this.nPos = nPos; i5Sya]FN
oSavedFile.seek(nPos); |cnps$fk~
} N2HD=[*cr
'ZI8nMY
~@6l7H6{
public synchronized int write(byte[] b,int nStart,int nLen) uxDM #
{ gjz-CY.hz
int n = -1; )=iv3nF?6N
try{ 0fvOA*UP
oSavedFile.write(b,nStart,nLen); o9sPyY$aQ
n = nLen; P%Vq#5
} VJTO:}Q
catch(IOException e) p[xGL } +\
{ /i27F2NQm
e.printStackTrace (); u_+iH$zA
} U+>M@!=
Nb9GrYIS
w< Xwz`O
return n; R)*DkL!
} R{bG`C8.d
a9p:k ]{
=$)M-;6
} |BZrV3;H
,>b>I#{
(?t}S.>g
/* <,GVrVH=t"
**SiteInfoBean.java .?QYqGcG
*/ P33xt~
package NetFox; Kw?3joy
7_ayn#;y
MA:5'n
public class SiteInfoBean { %EVgSF!r
8aWEl%
K6-M.I
private String sSiteURL; //Site's URL :zKMw=
private String sFilePath; //Saved File's Path njX$?V
private String sFileName; //Saved File's Name LYRpd
private int nSplitter; //Count of Splited Downloading File V+lF|CZb5
ML\>TDt
RfTGTz@H
public SiteInfoBean() {LF4_9 =
{//nSplitter的缺省值为5 =s4(Y
//default value of nSplitter is 5 +Z|3[#W
this("","","",5); J,CwC)
} =gQ9>An
A)C)5W
If,p!L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qJdlZW<
{ _;;Zz&c
sSiteURL= sURL; 2,q*[Kh1
sFilePath = sPath; ]$lt
sFileName = sName; esnq/
this.nSplitter = nSpiltter; 4_=2|2Wz[
={ms@/e/T
V9v20iX
} ,u2Qkw
s4"OsgP+
6qH0]7maI
public String getSSiteURL() {jz`K1
{ DaQl ip
return sSiteURL; =otO@22Np
} l,4O
a^p#M
_rwJ:r
public void setSSiteURL(String value) ;[Mvk6^'R
{ aE`d[dSG
sSiteURL = value; ccHf+=
} |]*3En:
O1z]d3x
aZWj52
public String getSFilePath() ;ItH2Lw<&
{ uX6yhaOp|
return sFilePath; Mu?|<#s
} XnQR(r)pR2
DpT9"?g7
I x%>aee
public void setSFilePath(String value) #0P_\X`E
{ gYB!KM *v
sFilePath = value; gA!@oiq@
} -r={P_E6
RSp wU;o6z
aj1]ZT\
public String getSFileName() <(xqw<)
{ G.rz6o;
return sFileName; N,Eap KG
} e7RgA1
?RsrY4P
@AEH?gOX
public void setSFileName(String value) ?*fY$93O
{ e73=*~kfR
sFileName = value; p{g4`o
} M^o_='\bE
{o}U"b<+Ra
1!<t8,W4
public int getNSplitter() R~\R>\
{ <\^0!v
return nSplitter; vYed_'_
} F8f}PV]b
cFUD$mp
SVe]2ONd
public void setNSplitter(int nCount) V?uT5.B2
{ \MP~}t}c
nSplitter = nCount; >h\y1IrAaG
} QyD0WC}i
} qjB:6Jq4q
'C1lP)S5
pU$k{^'UK
/* oac)na:O#
**Utility.java 0k]ApW
*/ !5`MiH
package NetFox; M@Th^yF+8H
x-BU$bx5
+A| Bc~2!
public class Utility { im<bo Mv
PG&t~4QM`
7>N~l
public Utility() ^A$=6=CX
{ !HY^QK
4p:d#,?r
1'~Xn 4 f
} #Rw!a#CX.
'nCVjO7o
//线程睡眠 {VcRur}&Y8
public static void sleep(int nSecond) J @Hg7Faz
{ |Y7SP]/`gB
try{ &dyQ6i$],
Thread.sleep(nSecond); '+88UFSq5
} mY"7/dw<v
catch(Exception e) O^L]2BVC
{ Ku(YTXtK
e.printStackTrace (); :zY4phR
} {wqT$( (<
} (GJtTp~2C4
4^F[Gp?
//日志 F%w!I 9
public static void log(String sMsg) TM)INo^
{ $vs],C"pX
System.err.println(sMsg); OX_y"]utU
} FM{f{2j
A@A8xn%
^ZwZze:2
public static void log(int sMsg) Q((&Q?Vi
{ \5ls <=S.
System.err.println(sMsg); uo"<}>iJ
} dyQ7@K.E
} Od!)MQ*,
j~q 7v `":
z?byNd8
/* UqK.b}s
**TestMethod.java JW>k8QjyN
*/ 7HPwlS
package NetFox; m{IlRf'
E7X6RB b
v;,W ^#`
public class TestMethod { K=gg<E<
u r$
;hT3N UCA
public TestMethod() Kb;*"@LX
{ ///xx/weblogic60b2_win.exe 8zK#./0\
try{ %1?t)Bg
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "~4V(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "laf:Ty1
SiteFileFetch fileFetch = new SiteFileFetch(bean); \BHZRytQF
fileFetch.start(); t&?jJ7 (&8
} 01.q9AGy
catch(Exception e){e.printStackTrace ();} <cTX;&0=
+XWTu!
72nZ`u
} \K$\-]N+
pwo$qs(p
+SFFwjI
public static void main(String[] args) T+Yv5l
{ ZqclmCi
new TestMethod(); a6Vfd&
} $}/tlA&e
} *7AB0y0k
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