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)); j^R~ Lt4
} :X'U`jE
for(int i=0;i<nEndPos.length-1;i++) )SO1P6
{ IBsO
nEndPos = nStartPos[i+1]; j$/uJ`
} X/C54%T ~
nEndPos[nEndPos.length-1] = nFileLength; N"Nd$4
} P^W$qy|
} x[h<3V"
(Su2\x
x[,wJzp\6
//启动子线程 M<me\s)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0.,&B5)
for(int i=0;i<nStartPos.length;i++) M}RFFg
{ kv FOk
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #._6lESK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]k%KTvX*G
nStartPos,nEndPos,i); pJ@DHj2@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?.'oxW
fileSplitterFetch.start(); R^w >aZoJ
} ?VHwYD.B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >w2WyYJYH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); p9bxhnn|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B7^n30+L
nEndPos = " + nFileLength); rzY@H }u
// fileSplitterFetch[nPos.length-1].start(); jMN@x]6w
7QRvl6cv
4Fht(B|
//等待子线程结束 6P[O8
//int count = 0; /[|md0,
//是否结束while循环 ;$&5I9N
boolean breakWhile = false; t7`Pw33#kY
a!]QD`
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while(!bStop) T<~[vjA
{ iZqFVr&JF
write_nPos(); LFry?HO,D
Utility.sleep(500); Rhxm)5+
breakWhile = true; d}G."wnG9,
6je%LHhL
s)ajy^6'M
for(int i=0;i<nStartPos.length;i++) 1$!K2=%OXj
{ ^oZs&+z
if(!fileSplitterFetch.bDownOver) L,ey3i7a\
{ ?;kc%Rz
breakWhile = false; =kkA
break; Z["nY&.sI
} ~5?n&pF
} D&lXi~Z%.
if(breakWhile) ,Onm!LI=
break; lfG&V +S1
gKH"f%lK
GHrT?zEX
//count++; z Clm'X/
//if(count>4) S:T>oFUot
// siteStop(); * =N6_
} Y:Tt$EQ
tqk6m# @(
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System.err.println("文件下载结束！"); ]cY'6'}Hz
} wAwH8xLU
catch(Exception e){e.printStackTrace ();} p{QKj3ov
} u>Kvub
?ew]i'9(
JA2}
//获得文件长度 ^bw~$*"j#
public long getFileSize() 2\W<EWJ@
{ -5*;J&.
int nFileLength = -1; ^x#RUv
try{ F476"WF
URL url = new URL(siteInfoBean.getSSiteURL()); ^mb*w)-p?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JO$]t|I
httpConnection.setRequestProperty("User-Agent","NetFox"); PH=8'GN
F4l6PGxF&\
QU;C*}0Zl
int responseCode=httpConnection.getResponseCode(); K&oO+G^f
if(responseCode>=400) {.)~4.LhQM
{ T1TZ+\
processErrorCode(responseCode); ~}l,H:jk@
return -2; //-2 represent access is error G#M]\)f%
} +0042Yi
LOo#
WYUU-
String sHeader; /JYi^rZ
x1ex}_\
h^X.e[
for(int i=1;;i++) l3$?eGGM
{ U?C{.@#w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); O/"&?)[v
//Utility.log(in.readLine()); 7im;b15j`'
sHeader=httpConnection.getHeaderFieldKey(i); FAGVpO[
if(sHeader!=null) U9OF0=g
{ aM1JG$+7G
if(sHeader.equals("Content-Length")) cHd39H9
{ wBGxJ\+M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d'J?QH!N0
break; N%i<DsK.u6
} yXmp]9$
} %'< qhGJ
else j;vaNg|vQ
break; 5~5ypQj
} ?':'zT
} t;6/bT-
catch(IOException e){e.printStackTrace ();} ~Q]M_,`M
catch(Exception e){e.printStackTrace ();} cK/odOi
>QPS0Vx[
$~\qoW<
Utility.log(nFileLength); D(GHkS*0q
6lFsN2
K6Ua~N^
return nFileLength; \Ki#"%S
} [K QZHIe
T!E LH!
S-dV
//保存下载信息（文件指针位置） rrq-so1u}
private void write_nPos() )Jn80~U|1
{ Q)8t;Kx
try{ <:o><f+
output = new DataOutputStream(new FileOutputStream(tmpFile)); wAPdu y[
output.writeInt(nStartPos.length); s2kynQ#a
for(int i=0;i<nStartPos.length;i++) MeS$+9jV(
{ 2F]MzeW
// output.writeLong(nPos); s os&
output.writeLong(fileSplitterFetch.nStartPos); ttRH[[E(
output.writeLong(fileSplitterFetch.nEndPos); zW.sXV,
} CAO{$<M5m
output.close(); MQu6Tm H
} vnpX-c
catch(IOException e){e.printStackTrace ();} /y@iaptC
catch(Exception e){e.printStackTrace ();} ,B!Qv3bn
} tam/FzVw
7Kjq1zl;
Reo0ZU>
//读取保存的下载信息（文件指针位置） wtyu"=
private void read_nPos() e2F7G>q:5
{ Z2 4 m
try{ @x4Dt&:"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); E$ rSrT(
int nCount = input.readInt(); g#*N@83C
nStartPos = new long[nCount]; aKO@_R,:
nEndPos = new long[nCount]; N<%,3W_-_
for(int i=0;i<nStartPos.length;i++) :Tl?yGF
{ N<WFe5
nStartPos = input.readLong(); sq$|Pad[
nEndPos = input.readLong(); 6Rj X
} RPQ)0.O7
input.close(); rY.:}D
} ,j<"~"] =
catch(IOException e){e.printStackTrace ();} zq&lxySa
catch(Exception e){e.printStackTrace ();} }% *g\%L
} i&KODhMpP
@YELqUb*
p IToy;]
private void processErrorCode(int nErrorCode) ?HTwTi5!)
{ /|f]L9)2<
System.err.println("Error Code : " + nErrorCode); e^TF.D?RS
} biD7(AK
f ;JSP
4vphLAm
//停止文件下载 4{pa`o3
public void siteStop() wr(?L7 $+
{ lB-7.
bStop = true; n66_#X
for(int i=0;i<nStartPos.length;i++) =G :H)i
fileSplitterFetch.splitterStop(); v;7u"9t
<}%*4mv
WDq3K/7\
} W#Z]mt B
} tK*f8X+q
//负责部分文件的抓取 xh$[E&2u
**FileSplitterFetch.java b;vO`
*/ y-mmc}B>N
package NetFox; xC(PH?_
^8)d8?}
&XP 0
import java.io.*; "-sz7}Mb
import java.net.*; DQd&:J@?
8*X8U:.0o
ewY X\
public class FileSplitterFetch extends Thread { ececN{U/
"fdG5|NJe
{H74`-C)W
String sURL; //File URL J4<*KL~a
long nStartPos; //File Snippet Start Position Nnw iH
long nEndPos; //File Snippet End Position ;N|6C+y
int nThreadID; //Thread's ID \=JKeL|6[S
boolean bDownOver = false; //Downing is over J$oJ
boolean bStop = false; //Stop identical ge|}'QKow
FileAccessI fileAccessI = null; //File Access interface ak zb<aT
]3G2mY;`"%
*zcH3a,9"x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `/O_6PQ}
{ NbdaP{{
this.sURL = sURL; l;4F,iI
this.nStartPos = nStart; qM)^]2_-
this.nEndPos = nEnd; QXCI+Fcg
nThreadID = id; SL*(ZEn"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }PVB+i M
} P<1zXs.H
F`l1I=;
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public void run() VQyDd~Za
{ uB BE!w_
while(nStartPos < nEndPos && !bStop) G+ToZ&f@
{ e=U7w7(s9
Yi:+,-Fso
B^ h!F8DC
try{ P06K0Fxf
URL url = new URL(sURL); yI!K quMC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); " 1Bn/Q
httpConnection.setRequestProperty("User-Agent","NetFox"); Q_Rr5/
String sProperty = "bytes="+nStartPos+"-"; OoE@30+
httpConnection.setRequestProperty("RANGE",sProperty); I/adzLQ
Utility.log(sProperty); J GdVSjNC
uAP|ASH9T
Lqt]
InputStream input = httpConnection.getInputStream(); R!O'DM+
//logResponseHead(httpConnection); M1:m"#=
a)]N#gx
/CP1mn6H
byte[] b = new byte[1024]; :\ S3[(FV
int nRead; VH/_0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I'";
{ u}$?r\H'(
nStartPos += fileAccessI.write(b,0,nRead); OtJS5A
//if(nThreadID == 1) iMSS8J
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #8A|-u=3
} 0R.@\?bhL
+ad 2
2IGAZ%%
Utility.log("Thread " + nThreadID + " is over!"); plca`
bDownOver = true; 4H'9y3dk
//nPos = fileAccessI.write (b,0,nRead); WVVqH_
} +XsY*$O
catch(Exception e){e.printStackTrace ();} qz 'a.]{=
} Wl1%BN0>
} j=7]"%
;fuy}q8@7
hod|o1C&
//打印回应的头信息 E @7! :
public void logResponseHead(HttpURLConnection con) u{si
{ T"$"`A"
for(int i=1;;i++) n[<Vj1n
{ {d)+a$qj
String header=con.getHeaderFieldKey(i); {2,V3*NF
if(header!=null) ^'}Td~(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MSA*XDnN
Utility.log(header+" : "+con.getHeaderField(header)); >y1/*)O9~
else wFh{\
break; ZEB1()GB
} %FwLFo^v
} PffRV7qU0
BQm H9g|2
T =:^k+
public void splitterStop() J &c}z4
{ ]_-<[0
bStop = true; RAe:$Iv$!v
} "UE'dWz
UXd\Q''
"kMpa]<c-6
} zU(U^
Ls9G:>'rR
#CM2FN:W
/* h5F1mr1Sa
**FileAccess.java `A#r6+
*//文件访问(定位，写) x.'O_7c0:
package NetFox; oYu5]ry
import java.io.*; >J4_/p>Qs
*-2u0%
^K3{6}]
public class FileAccessI implements Serializable{ Q?vGg{>
*'Ch(c:rtH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7-)Y\D
RandomAccessFile oSavedFile; x;ujR<
long nPos; mWtwp-
yHCBf)N7\
/7*u!CNm
public FileAccessI() throws IOException hF6EOCY6D
{ )4j#gHN\
this("",0); T1Xm^{
} k)4
~dC^|
)5B90[M|t
public FileAccessI(String sName,long nPos) throws IOException Hq=RtW2
{ 4rv3D@E
oSavedFile = new RandomAccessFile(sName,"rw"); Ix"uk6 h
this.nPos = nPos; i2EB.Zlv
oSavedFile.seek(nPos); Ehg5u'cj
} Y]P]^3
Dk:Zeo]+my
HdVGkv/
public synchronized int write(byte[] b,int nStart,int nLen) * ,,D%L
{ 2&dtOyxo>
int n = -1; JI(8{ f
try{ /+%1Kq.hP
oSavedFile.write(b,nStart,nLen); Kg9REL@,s
n = nLen; LTrn$k3}
} O0wD"V^W
catch(IOException e) --y.q~d
{ i4AmNRs
e.printStackTrace (); C5F}*]E[y
} hb`(d_=7F
%A?Ym33
2Ui)'0
return n; {4UlJ,Z.n
} "#(]{MY
IS"UBJ6p
7x`uGmp1
} FD[*mCGZ
H=EvT'g
BB9Z?}
/* HnrT;!C~
**SiteInfoBean.java B2VUH..am
*/ #AE'arT<
package NetFox; tFXG4+$D
Ot5 $~o
jPhOk>m
public class SiteInfoBean { 9J*m!-hOY
(m})V0/`
3. fIp5g
private String sSiteURL; //Site's URL zkB_$=sbn#
private String sFilePath; //Saved File's Path SxNs
private String sFileName; //Saved File's Name 8z\WyDz
private int nSplitter; //Count of Splited Downloading File cvi+AZ=
C^]bXIb
,Epg&)wC]
public SiteInfoBean() mq>Ag
{//nSplitter的缺省值为5 "@DCQ
//default value of nSplitter is 5 $}N'm
this("","","",5); XswEAz0=
} Sw>AgES
zAS&L%^tV
3%>"|Ye}A
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^<7)w2ns
{ o^2.&e+dQ
sSiteURL= sURL; %/jmQ6z^
sFilePath = sPath; (yn!~El3
sFileName = sName; 'Q?nU^:F#
this.nSplitter = nSpiltter; IKH#[jW'IB
|v:8^C7
d'J))-*#UO
} $D1Pk
*[k7KG2_U
,@8>=rT
public String getSSiteURL() 5,k&^CK}
{ U5%EQc-"P
return sSiteURL; lhKd<Y"
} PKty'}KF
3@_je)s
VWaI!bK
public void setSSiteURL(String value) UIIR$,XB
{ 8}nA8J
sSiteURL = value; }r9f}yX9Q
} 3;@t{rIin
esWgYAc3{
pu=Q;E_f[
public String getSFilePath() 32:q'
{ #Q"el3P+q
return sFilePath; 6uOR0L
} 0'%R@|
9co1+y=i{
lmgMR|v
public void setSFilePath(String value) T[*=7jnJQ
{ 7JQ5OC3
sFilePath = value; UXnd~DA
} z{7&=$
Y6,< j|
=AUR]&_B
public String getSFileName() ;spuBA)[X
{ -6aGcPq
return sFileName; 5a&[NN
} fYl$$.
?yU|;my
&Dgho
public void setSFileName(String value) 0,{Dw9W:
{ j"7 z
sFileName = value; [}N?'foLb
} ]+{Cy\*kR
?S36)oZzg
oOnk,U
public int getNSplitter() W -8<sv$b
{ {;=I69X
return nSplitter; "9>~O`l,
} HBXp#$dPc
=(3Qbb1i
l%oie1g l
public void setNSplitter(int nCount) ]Jq1b210
{ y9?BvPp+
nSplitter = nCount; o5-oQ_j
} 7AX<>^
} /xWkP{
t:9}~%~
g~S>_~WL
/* Eo!1 WRruF
**Utility.java a]Bm0gdrO
*/ tK`sVsm>
package NetFox; XTUxMdN
.R#p<"$I
j*Ta?'*
public class Utility { G29PdmY$<
O$V 6QJ
={o>g'
public Utility() s=! y%
{ <=l!~~%
qH: ` O%,
\f}S Hh
} Zm>Q-7r9
4/&Us
//线程睡眠 \SHYwD}*Pr
public static void sleep(int nSecond) A|,\}9)4X[
{ y+)][Wa0
try{ 5hUYxF20h8
Thread.sleep(nSecond); T2P0(rEz
} ?Lbwo<E
catch(Exception e) ;XMbjWc
{ Zrr3='^s
e.printStackTrace (); ;e_dk4_
} Ou"QUn|
} vQ#$.*Cvn
G|Yw a=
//日志 !h4S`2oZ/
public static void log(String sMsg) mnzamp
{ &cV$8*2b^
System.err.println(sMsg); $W<H[k&(B
} j7K9T
7[rn ,8@
rRRiqmq
public static void log(int sMsg) 3k`"%R.H
{ idMb}fw>
System.err.println(sMsg); 'ejuzE9
} m\(4y Gj
} R rs?I,NV
cKEf- &~
B.-5$4*s
/* 9<I@}w
**TestMethod.java F#Uxl%h
*/ >eQ;\j
package NetFox; (YVl5}V
W$O^IC
%*wJODtB|
public class TestMethod { H$>D_WeJ
hZ Gr/5f
6;60}y
public TestMethod() }{[H@uhjH
{ ///xx/weblogic60b2_win.exe FbO-K-
try{ $Q{)AN;m
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DmEmv/N=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?7 e|gpQ|
SiteFileFetch fileFetch = new SiteFileFetch(bean); tSV}BM,
fileFetch.start(); 7h?PVobe
} 7(rTGd0
catch(Exception e){e.printStackTrace ();} =uQCm#
ywXerz7dUk
f50qA;7k
} O&.^67\|
oUIa/}}w5
<mjH#aSy
public static void main(String[] args) gQ3Co./
{ O@{ JB
new TestMethod(); :0$(umW@I"
} yw^t6E
} _v{,vLH
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