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)); sW'6}^Q
} -%=RFgU4
for(int i=0;i<nEndPos.length-1;i++) f?5A"-NS
{ Ge1duRGa
nEndPos = nStartPos[i+1]; GoL|iNW`
} req-Q |
nEndPos[nEndPos.length-1] = nFileLength; (GNEYf|
} L]*`4L
} 7@@<5&mN
LUG9 #.
p2^)2v
//启动子线程 j%u8=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E@mkm
for(int i=0;i<nStartPos.length;i++) ,P~QS
{ !U[:5@s06
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 369Zu4|u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FH[#yq.Pr
nStartPos,nEndPos,i); + "zYn!0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )r pD2H
fileSplitterFetch.start(); {s9<ej~<R
} \H[Yyp4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d QDLI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qzHU)Ns(_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FSe5k5
nEndPos = " + nFileLength); L,W:,i/C
// fileSplitterFetch[nPos.length-1].start(); 7P c(<Ui+
{yU0D*#6
cTy'JT7
//等待子线程结束 J7Sx!PQ
//int count = 0; u9,=po=+7f
//是否结束while循环 JeL~]F
boolean breakWhile = false; 18rp; l{
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LGXZx}4@;
while(!bStop) 1Df,a#,y"
{ %2,/jhHL
write_nPos(); X]MTaD.t
Utility.sleep(500); FF jRf
breakWhile = true; s_S$7N`ocS
G4O3h Y.`
lm!FM`m
for(int i=0;i<nStartPos.length;i++) CMFC"eSe
{ <irpmRQr
if(!fileSplitterFetch.bDownOver) xlk5Gob*
{ ;8uHRcdQ
breakWhile = false; E;$$+rA
break; ]y}Zi/zh
} d&?F#$>7|
} L@+Z)# V
if(breakWhile) h*l cEzG?A
break; sX Z4U0#
zNwc((
,k\/]9
//count++; *iYMX[$
//if(count>4) vU7&'ca
// siteStop(); EFeAr@nj
} T"IW Jpc
1B(G]o_>!
PH[4y:^DN
System.err.println("文件下载结束！"); i:{:xKiCa
} IE|,~M2
catch(Exception e){e.printStackTrace ();} Pm~,Ky&Hl
} 9V.+U7\w
C!hXEtK
g(1"GKg3K
//获得文件长度 Y1|^>C#a
public long getFileSize() |MVV +.X
{ VYHOk3
int nFileLength = -1; Ls(&HOK[p
try{ KjC[q
URL url = new URL(siteInfoBean.getSSiteURL()); 8cB=}XgYS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @::lJDGVv
httpConnection.setRequestProperty("User-Agent","NetFox"); 50COL66:7
G%Y*q(VrEu
\_?yzgf
int responseCode=httpConnection.getResponseCode(); (&k')ff9K
if(responseCode>=400) .a5X*M]
{ s* @QT8%
processErrorCode(responseCode); 3mybG%39
return -2; //-2 represent access is error am3V9"\
} @kS|Jz$iY
w~ijD ^g
2UQN*_
String sHeader; FXcc1X/
ta@ISRK
wQ@Zwbx
for(int i=1;;i++) f]hBPkZ6
{ haN"/C^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2lF WW(
//Utility.log(in.readLine()); A(PE
sHeader=httpConnection.getHeaderFieldKey(i); n&(3o6i'
if(sHeader!=null) ,#=eu85'
{ ixg\[5.Q+
if(sHeader.equals("Content-Length")) vs*>onCf
{ *13g<#$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XadG\_?t`
break; L(W%~UGN V
} LE<:.?<Z-
} PKl]GegP
else i[mC3ghM6,
break; !'+\]eA
} :{x!g6bK@
} t$tsWAmiA[
catch(IOException e){e.printStackTrace ();} ' l|41wxk
catch(Exception e){e.printStackTrace ();} u<x[5xH+
LAj}kW~
Oib[\O7[z
Utility.log(nFileLength); bN]\K/
tWcizj;?wK
cPV5^9\T
return nFileLength; N|bPhssFw
} 7sCR!0
E*Pz <
| pF5`dX
//保存下载信息（文件指针位置） F@B
private void write_nPos() 4 `j,&=
{ ys:1Z\$P
try{ 4F}g(
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?a*fy}A|
output.writeInt(nStartPos.length); D1oaG0
for(int i=0;i<nStartPos.length;i++) od;Bb
{ h<+PP]l=
// output.writeLong(nPos); -7&^jP\,
output.writeLong(fileSplitterFetch.nStartPos); lO%MyP
output.writeLong(fileSplitterFetch.nEndPos); s@/B*r9
} vd2uD2%con
output.close(); b5lk0jA
} :y4)qF
catch(IOException e){e.printStackTrace ();} <)r,CiS
catch(Exception e){e.printStackTrace ();} 'm
} ZD$-V3e`
j0ci~6&b3_
3WQRN_
//读取保存的下载信息（文件指针位置） v(i1Z}*b
private void read_nPos() MtMvpHk
{ .CIbpV?T
try{ ORUWslMt
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F<6KaZ|
int nCount = input.readInt(); a7ub.9>
nStartPos = new long[nCount]; EGp~Vo-
nEndPos = new long[nCount]; )6O\WB|
for(int i=0;i<nStartPos.length;i++) %i;r]z-
{ {JCSR2BB
nStartPos = input.readLong(); W@R$'r,@O
nEndPos = input.readLong(); g(ZeFOn
} jydp4ek_n
input.close(); 2U-#0,ll]
} p.6$w:eV
catch(IOException e){e.printStackTrace ();} Y\ #.EVz
catch(Exception e){e.printStackTrace ();} i{Y=!r5r
} Z!q2F%02FO
Z"teZ0H
*+_fP|cv
private void processErrorCode(int nErrorCode) ;t.SiA
{ QO1A976o
System.err.println("Error Code : " + nErrorCode); hNu>s
} dSA [3V
WZ-4^WM=!
r[C3u[
//停止文件下载 F{a0X0ru~
public void siteStop() jKY Aid{-
{ *7:u-}c!
bStop = true; l8hvq(,{
for(int i=0;i<nStartPos.length;i++) MEdIw#P.}{
fileSplitterFetch.splitterStop(); 0 .6X{kO
P#vv+]/
3B!&ow<rt
} a'*5PaXU@/
} ZuF4N=;
//负责部分文件的抓取 ECmHy@(
**FileSplitterFetch.java >oM9~7f
*/ =]5DYRhX]
package NetFox; y]~+`9
S0Rf>Eo4
G#9o?
import java.io.*; ?3B t;<^
import java.net.*; a<a&63
Lz#$_Am'H
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public class FileSplitterFetch extends Thread { ?<>,XyY
} K+Q9<~u
hJ$C%1;
String sURL; //File URL {kRDegby
long nStartPos; //File Snippet Start Position 1pYmtr
long nEndPos; //File Snippet End Position 0`g}(}'L
int nThreadID; //Thread's ID `JY>v io
boolean bDownOver = false; //Downing is over bJG!)3cx
boolean bStop = false; //Stop identical b]tA2~e
FileAccessI fileAccessI = null; //File Access interface ]ut-wqb{p
o3\SO
u~naVX\3b
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~vjr;a(B
{ 82Z[eo
this.sURL = sURL; _.Z&<.lJ
this.nStartPos = nStart; <'o'H
this.nEndPos = nEnd; T}b( M*E
nThreadID = id; :?&WKW
fileAccessI = new FileAccessI(sName,nStartPos);//定位 PJSDY1T
} &}L36|A:
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\M'bY:
public void run() m_r@t*
{ k^'d@1z;C
while(nStartPos < nEndPos && !bStop) gN!E*@7
{ :#Ex3H7
Im' :sJ31
*$4A|EA V
try{ mvL0F%\.\
URL url = new URL(sURL); +s*l#'Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N,sqrk]
httpConnection.setRequestProperty("User-Agent","NetFox"); H8o%H=I%
String sProperty = "bytes="+nStartPos+"-"; 8 /RfNGY
httpConnection.setRequestProperty("RANGE",sProperty); >2/wzsW
Utility.log(sProperty); WO+?gu
#<WyId(
<De3mZb
InputStream input = httpConnection.getInputStream(); cciAMQhA
//logResponseHead(httpConnection); 0c\|S>g[
6ljRV)
ELkOrV~a{:
byte[] b = new byte[1024]; 0]2B-o"kI
int nRead; LBbo.KxAe3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $@:>7Y"
{ ]` &[Se d
nStartPos += fileAccessI.write(b,0,nRead); E^EU+})Ujr
//if(nThreadID == 1) ;*37ta
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q_T?G e
} :)+@qxTy
} {gWTp
oZ*=7u
Utility.log("Thread " + nThreadID + " is over!"); ffoo^1}1
bDownOver = true; }Nd`;d
//nPos = fileAccessI.write (b,0,nRead); Q 2SSJ
} n[MIa]dK
catch(Exception e){e.printStackTrace ();} o,''f_tRQ|
} $jm>tW&;
} ^b|Nw:
=Zb"T5E
$E9daUt8"J
//打印回应的头信息 ad3z]dUZ9
public void logResponseHead(HttpURLConnection con) q$u\ q.
{ beHCEwh
for(int i=1;;i++) G(|(y=ck
{ bh;b` 5
String header=con.getHeaderFieldKey(i); xn x1`|1u
if(header!=null) ]\9B?W(#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OL ]T+6X
Utility.log(header+" : "+con.getHeaderField(header)); SFk11
else ,TfI
break; M\.T 0M_
} +'&_V011<
} Y5A~iGp8E
,C'w(af@}
W|-N>,G
public void splitterStop() W1vAK
{ p`l[cVQ<
bStop = true; \,cKt_{ u
} J%O4IcE
RzY`^A6G6
m|cWX"#g
} m9<[bEO<$
w<F;&';@h
'B<qG<>
/* 8hdAXWPn
**FileAccess.java {@K2WB
*//文件访问(定位，写) xMfv&q=k@
package NetFox; 6`5 @E\"E
import java.io.*; #ZnX6=;X
vhquHy.qi#
Q"K>ML>0
public class FileAccessI implements Serializable{ )}it,<
J0*]6oD!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Nec(^|[
RandomAccessFile oSavedFile; ~ew**@N
long nPos; !9<RWNKV)Y
=!P?/
g /@yK
public FileAccessI() throws IOException UG?C=Tf
{ 5@Lxbe( q
this("",0); 0)Um W{
} VU0tyj$
J)yy}[Fx
lbuW*)
public FileAccessI(String sName,long nPos) throws IOException =UKR<@QrK
{ .gkPG'm[
oSavedFile = new RandomAccessFile(sName,"rw"); AoOG[to7
this.nPos = nPos; SnF[mN'
oSavedFile.seek(nPos); _Il9s#NA%
} 6r-n6#=
3w:Z4]J
jUR#
public synchronized int write(byte[] b,int nStart,int nLen) Z2j*%/
{ A"3&EuvU
int n = -1; \NQ)Po@z
try{ gWv+i/,
oSavedFile.write(b,nStart,nLen); [QqNsco)
n = nLen; Q]g4gj
} GxDF7 z%&
catch(IOException e) ?nSp?m;
{ NUnc"@
e.printStackTrace (); @)'@LF1Z
} F)iGD~
nIDsCu=A
>/`cmNmb
return n; bq&S?! =s
} 68GGS`&
dUtIAh-j
-Tkd@
} Y&!]I84]
898wZ{9
9-iB?a7{.
/* E!~2\qKT
**SiteInfoBean.java &b6@_C9
*/ eF;1l<<
package NetFox; b`|MK4M(
Tl7:}X<?
t7+Ic
public class SiteInfoBean { '=5_u
5 /jY=/0.a
yGG\[I;7
private String sSiteURL; //Site's URL v*fc5"3eO
private String sFilePath; //Saved File's Path ~_j%nJ &2
private String sFileName; //Saved File's Name 59Q Q_#>
private int nSplitter; //Count of Splited Downloading File 32|L $o
$H@)hY8wA
p'!,F; xX
public SiteInfoBean() <07W&`Dw
{//nSplitter的缺省值为5 sr@XumT
//default value of nSplitter is 5 ^W[`##,{Od
this("","","",5); 4-rI4A<
} L{,7(C=
j=QR*8*
GhQ`{iJM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) kDP^[V P+
{ 5{/Pn%5
sSiteURL= sURL; .-~%w
sFilePath = sPath; $#JVI:
sFileName = sName; *]{I\rX
this.nSplitter = nSpiltter; 78J.~v/
<\>ak7m
RYJc>
} SVWSO
L=wFo^N
rkc%S5we
public String getSSiteURL() 54cgX)E[x
{ sH,)e'0
return sSiteURL; {ZEXlNPww
} Dlf=N$BL7d
iwjl--)@K
5qfKV&D
public void setSSiteURL(String value) 9l_?n@
{ (C|V-}/*m
sSiteURL = value; "<$vU_
} t}+c/ C%b=
oqHm:u^2
M &EJFpc*
public String getSFilePath() HF[%/Tu
{ >P"/nS"nn
return sFilePath; x2c*k$<p
} A?k,}~
'wlP`7&Tn
+9rbQ?'
public void setSFilePath(String value) >t2)Z|1
{ -vfu0XI~
sFilePath = value; f_2^PF>?
} 5nqdY*
PlRs-%d
Sz@?%PnU|
public String getSFileName() k#NMD4(%O
{ cD@lorj
return sFileName; Y8'_5?+ 0
} QjN3j*@
IMrOPwjc
[y;ZbfMP|o
public void setSFileName(String value) (MiOrzT
{ -mo ' $1
sFileName = value; %)ov,p|
} T\CQ
WREGRy
(`/i1#nR
public int getNSplitter() Z@O e}\.$
{ 6v)eM=
return nSplitter; `|?$; )
} @7 HBXP
\J&#C(pn
:Zo2@8@7
public void setNSplitter(int nCount) 5MU@g*gj,C
{ *<QL[qyV
nSplitter = nCount; 9sU,.T
} l<_mag/j9o
} '6J$X-
Eakjsk
H4A+Dg,
/* 3zF7V:XH
**Utility.java S9+gVR8]C
*/ Dq4}VkY
package NetFox; J&1N8Wk)
xi=uXxl
2]f.mq_PD
public class Utility { 2+cicBD
lS*.?4zX
m?G+#k;K
public Utility() uxiX"0)g>
{ o;I86dI6C
iGNKf|8{
9gayu<J
} IFoN<<7/2$
oioN0EuDk
//线程睡眠 Ps4A B#3
public static void sleep(int nSecond) `&7?+s
{ ]r5Xp#q2
try{ wk/U"@lq
Thread.sleep(nSecond); Q[tz)99~
} 0LuY"(LR
catch(Exception e) S^=/}PT'
{ 30`H Xv@
e.printStackTrace (); m]pvJJ@
} <QLj6#d7Y
} Y%8QFM
RM$S|y{L
//日志 me\)JCZpb{
public static void log(String sMsg) 5*Iz3vTq
{ ')~HOCBSE
System.err.println(sMsg); s5#g[}dj
} 824%]i3
:$d3a"]
T,@7giQg@
public static void log(int sMsg) 0_izTke
{ y%Ah"UY
System.err.println(sMsg); -q|M=6gOs
} c3-bn #
} Gl1$W=pR:
5|z[%x~f
$7g(-W
/* ^@eCT}p{
**TestMethod.java zxHfQ(
*/ Y:BrAa[
package NetFox; 24l9/v'
K*RRbtb
FQ^uX]<3j
public class TestMethod { ^S$w,
5OE?;PJ(
:7*\|2zA
public TestMethod() r${a S@F
{ ///xx/weblogic60b2_win.exe ^r$5];n
try{ $yJfAR
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ga%77t|jm3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q"uu&JC
SiteFileFetch fileFetch = new SiteFileFetch(bean); aW5~z^I
fileFetch.start(); i?9Lf
} Pw1H)<X
catch(Exception e){e.printStackTrace ();} IA^DfdZY
-7Wmq[L/
0Z(b/fdS
} VlvDodV
ypVr"fWB
e@YR/I8my
public static void main(String[] args) dq&d>f1
{ GrIdQi^8
new TestMethod(); _: x$"i
} e&nw&9vo
} ),|bP`V
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