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)); ,^iT,MgNNf
} 10dK%/6/O
for(int i=0;i<nEndPos.length-1;i++) _Axw$oYS
{ ]~m=b`o
nEndPos = nStartPos[i+1]; tr 8Q{
} N:^4OnVR
nEndPos[nEndPos.length-1] = nFileLength; 00W_XhJ
} }D~m%%,
} &@&^k$du8q
[eF|2:
Y% [H:
//启动子线程 &6Wim<*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; CZv^,O(M?2
for(int i=0;i<nStartPos.length;i++) mh_GYzd
{ \bSakh71
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H/#WpRg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), fK4O N'[R:
nStartPos,nEndPos,i); )]}68}9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Df$Yn
fileSplitterFetch.start(); z_&T>ME
} C5^N)-]"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,l)AYu!q4F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k"`^vV[{F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (yeN> x}_
nEndPos = " + nFileLength); Iak06E
// fileSplitterFetch[nPos.length-1].start(); G#^6H]`[J:
G|$n,X1O(
dfeN_0`-
//等待子线程结束 B<!wh
//int count = 0; 1N8YD .3
//是否结束while循环 # WL5p.
boolean breakWhile = false; xiQd[[(sM
Zvz}Z8jW
JZNvuPD
while(!bStop) =?B[oq
{ BI6`@}%7>
write_nPos(); na/,1iI<
Utility.sleep(500); oA ]F`N=
breakWhile = true; # f{L;
jAFJ?L(
7mS_Cz+cB
for(int i=0;i<nStartPos.length;i++) -uK@2}NZ
{ ubi6=
if(!fileSplitterFetch.bDownOver) Gc!&I+kd
{ '^t(=02J
breakWhile = false; H!g9~a
break; 4kLTKm:G
} hniTMO
} ^W,x
if(breakWhile) kh*td(pfP9
break; FwSV \N+#'
qB=%8$J
NEMC
//count++; $5yH8JU
//if(count>4) D|5Fo'O^AV
// siteStop(); r%oXO]X
} YcuHYf5
Ils^t
)0@&pEObm
System.err.println("文件下载结束！"); w3oe.hWP3N
} 9O#?r82
catch(Exception e){e.printStackTrace ();} 8F`799[p
} }KL( -Ui$
jowR!rqf
ZltY_5l
//获得文件长度 ~D Ta%J
public long getFileSize() QcDtZg\
{ 8J#TP7;
int nFileLength = -1; HFf9^
try{ ![@\p5-e
URL url = new URL(siteInfoBean.getSSiteURL()); )pt#Pu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NY~y:*:Q
httpConnection.setRequestProperty("User-Agent","NetFox"); "/U~j4O
[]eZO_o6j
bMF`KRP2
int responseCode=httpConnection.getResponseCode(); 9RN! <`H
if(responseCode>=400) qgLj^{
{ ]a=Bc~g91
processErrorCode(responseCode); !xZ`()D#
return -2; //-2 represent access is error Ja6PX P]'
} qeZ*!H6-
u'EzYJ7
E@$HO_;&
String sHeader; c`G~.paY|
V4 Wn
~Aq$GH4
for(int i=1;;i++) %L;'C v
{ Q|J$R
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); O0#9D'{
//Utility.log(in.readLine()); ~f>km|Q{u
sHeader=httpConnection.getHeaderFieldKey(i); FiJU *
if(sHeader!=null) VYN1^Tp
{ lvZ:Aw r
if(sHeader.equals("Content-Length")) q\6ZmKGnT
{ ~w9ZSSb4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'gwh:8Xc
break; |G]M"3^
} s;-%Dfn
} at `\7YfQp
else /WKp\r(Hp
break; ~,.}@XlgT.
} VN9C@ ;'$
} /SZg34%
catch(IOException e){e.printStackTrace ();} 'xY@I`x
catch(Exception e){e.printStackTrace ();} s\dF7/b
KFMEY\6\h
J~vK`+Zs
Utility.log(nFileLength); !>5!Fb=Sy
Enj],I
)Dq/fW
return nFileLength; ;iEFG^'tG
} KUqD<Jj?
HNtl>H
?rn#S8nNx<
//保存下载信息（文件指针位置） y7CrH=^jc
private void write_nPos() }PDNW
{ 0if~qGm=!
try{ PXYo@^ 3
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9fL48f$
output.writeInt(nStartPos.length); SNK _
for(int i=0;i<nStartPos.length;i++) B}y-zj;T
{ 9>"To
// output.writeLong(nPos); kdrya
output.writeLong(fileSplitterFetch.nStartPos); M%8:
output.writeLong(fileSplitterFetch.nEndPos); h0fbc;l
} GM<r{6Qy
output.close(); &<sN(;%0R
} Q@lJ|
catch(IOException e){e.printStackTrace ();} 7 n=fB#!*3
catch(Exception e){e.printStackTrace ();} ( nH3
} U0:tE>3`
2x7%6'
B3^4,'
//读取保存的下载信息（文件指针位置） 3;J)&(j0
private void read_nPos() {~ngI<
{ A;A>Q`JJF
try{ to
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 'j+J?Y^
int nCount = input.readInt(); A"@C }f
nStartPos = new long[nCount]; 9H<6k*
nEndPos = new long[nCount]; LAwl9YnG:
for(int i=0;i<nStartPos.length;i++) "3i=kvdz
{ S?5z
nStartPos = input.readLong(); YbrsXp"
nEndPos = input.readLong(); qeyBZ8BG
} HEjrat;5
input.close(); Wh)QCp0|n
} X>#!s Lt
catch(IOException e){e.printStackTrace ();} QxmVImn"
catch(Exception e){e.printStackTrace ();} 5!PU+9Kh
} m{bw(+r
+FoR;v)z=F
t3 q0|S
private void processErrorCode(int nErrorCode) ci^+T *
{ !.'@3-w]
System.err.println("Error Code : " + nErrorCode); S/ Y1NH
} hD>O LoO
^xGdRaU#
;ml;{<jI
//停止文件下载 )up!W4h6o
public void siteStop() Z=Oo%lM6B
{ 2EOt.4cP
bStop = true; 4V7{5:oa
for(int i=0;i<nStartPos.length;i++) ,zLi{a6
fileSplitterFetch.splitterStop(); dfo{ B/+
{qm(Z+wcmb
b7/1]
} Y24:D7Q
} >4.{|0%ut
//负责部分文件的抓取 j!;?=s
**FileSplitterFetch.java G!54 e
*/ PT|W{RlNl
package NetFox; $zTjh~ 9
dOFxzk,g&R
wL2d.$?TEg
import java.io.*; CW Y'q
import java.net.*; tF)aNtX4^
}Jgz#d
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public class FileSplitterFetch extends Thread { :G|Jcl=r
@Zs}8YhC
u8*Uia*vwH
String sURL; //File URL hIw<gb4J%
long nStartPos; //File Snippet Start Position qPpC)6-Q
long nEndPos; //File Snippet End Position j0k"iv
int nThreadID; //Thread's ID AR?J[e
boolean bDownOver = false; //Downing is over AO9F.A<T5
boolean bStop = false; //Stop identical X.,1SYG[
FileAccessI fileAccessI = null; //File Access interface L!-@dz
4b8!LzKS
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException EM*YN=So
{ Ftm%@S?
this.sURL = sURL; YXJjqH3
this.nStartPos = nStart; 'hL\xf{
this.nEndPos = nEnd; p3*}!ez4
nThreadID = id; S2"p(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 laqW {sX^5
} DY6wp@A
KX9+*YY,
">kfX1LT
public void run() N`/6 By
{ W:P4XwR{
while(nStartPos < nEndPos && !bStop) Cl]E rg
{ ~?dPF;.6_
aU2O5z&
{vAq08
try{ a Kb2:1EQ
URL url = new URL(sURL); A1p;Ye>o~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P}H7WH
httpConnection.setRequestProperty("User-Agent","NetFox"); S@zsPzw
String sProperty = "bytes="+nStartPos+"-"; E'e#axF;
httpConnection.setRequestProperty("RANGE",sProperty); Hq^sU%
Utility.log(sProperty); >U9*
jd=k[Yqr
@3{'!#/
InputStream input = httpConnection.getInputStream(); \{n]&IjA
//logResponseHead(httpConnection); i 4eb\j
1P4jdp=~
oa+Rr&t'
byte[] b = new byte[1024]; 0?ZJJdI3
int nRead; _ 9Tv*@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <?,o {
{ *;O$=PE
nStartPos += fileAccessI.write(b,0,nRead); ;*+jCL2F
//if(nThreadID == 1) /+Xv(B
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?T70C9
} }7vX4{Yn
@q2Yka
:h N*
Utility.log("Thread " + nThreadID + " is over!"); &-9wUZ
bDownOver = true; rZ1${/6
//nPos = fileAccessI.write (b,0,nRead); iD_NpH q
} y`=A$>A
catch(Exception e){e.printStackTrace ();} yjpV71!M
} ?K{CjwE.M
} ycRy!0l
dV8mI,h
qr(SAIX"
//打印回应的头信息 <O>r e3s
public void logResponseHead(HttpURLConnection con) 8OZc:/
{ U=p,drF,A
for(int i=1;;i++) [a5L WW
{ vj^vzFbK
String header=con.getHeaderFieldKey(i); ;&P%A<[`
if(header!=null) JMw1qPJQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r<Ll>R
Utility.log(header+" : "+con.getHeaderField(header)); )`^t,x<S
else d$kGYMT"
break; s*:J=+D]G
} VLN=9
} :sFP{rFx~
CfoSow-
sn/^#Aa=N
public void splitterStop() v'S}&zmF]
{ (J][(=s;a
bStop = true; :p(3Ap2TY
} c{6!}0Q4
bJ]g2C7`36
+o!".Hp
} q.t>:`
7Xm pq&g
U/m6% )Yx(
/* ;c_X ^"d
**FileAccess.java [(w_!|S
*//文件访问(定位，写) ^/2n[orl5
package NetFox; P6zy<w
import java.io.*; pA+W 8v#*
1fm\5/}'`1
t*<.^+Vd
public class FileAccessI implements Serializable{ *n N;!*J
Xp{+){Iu
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,Zb]3
RandomAccessFile oSavedFile; *;(LKRV
long nPos; B[!wo
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public FileAccessI() throws IOException qXkc~{W_
{ HjbC>*
this("",0); 0~H(GG$VH
} vL`wn=
OO]~\j
Ix^xL+Tm
public FileAccessI(String sName,long nPos) throws IOException j Aw&5,
{ B5IS-d
oSavedFile = new RandomAccessFile(sName,"rw"); r Ka7[/
this.nPos = nPos; x1]^].#Eo
oSavedFile.seek(nPos); 0"kNn5
} +iir]"8
vX]\Jqy
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public synchronized int write(byte[] b,int nStart,int nLen) =K=FzV'_~
{ 0iinr:=u
int n = -1; T/V8&'^i
try{ gdRwh
oSavedFile.write(b,nStart,nLen); @3K)VjY7
n = nLen; 5u MP31
} 4$+1jjC]>~
catch(IOException e) 8=FP92X
{ KTD# a1W
e.printStackTrace (); KY<>S/
} B@Ez,u5
+#}I^N
:seo0w]
return n; suN{)"
} =LL5E}xP
B t-o:)pa
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} r;t0+aLc*
AdesR-e$R
DmM<Kkg.J
/* lplEQ]J|
**SiteInfoBean.java WLQm|C,
*/ (YF`#v6
package NetFox; 'xm_oGWE
SG2s!Ht
~EG`[cv
public class SiteInfoBean { {O*WLZ{0
x'{L%c>L
)C5<puh
private String sSiteURL; //Site's URL m:59f9WXA
private String sFilePath; //Saved File's Path :D8V*F6P
private String sFileName; //Saved File's Name -tAdA2?G
private int nSplitter; //Count of Splited Downloading File mVg-z~44T
<LIL{g0eX
UJ1iXV[h"
public SiteInfoBean() )d!,,o
{//nSplitter的缺省值为5 6e(|t2^
//default value of nSplitter is 5 w?d~c*4+
this("","","",5); QM=M<~<Voh
} 8Gzc3
hn#i,XnY
ya0L8`q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !jL|HwlA
{ UB }n=
sSiteURL= sURL; v=EV5#A
sFilePath = sPath; 0'wB':v
sFileName = sName; t&T0E.kh*X
this.nSplitter = nSpiltter; &[f.;1+C
~0,Utqy
s9>f5u?dK
} Q0i.gEwe
iY1%"x
@cA`del
public String getSSiteURL() ;|6kFBGC"+
{ m!3b.2/h
return sSiteURL; BoE;,s>]NW
} y8'WR-;
i[/g&fx
wN\%b}pp
public void setSSiteURL(String value) o@mZ6!ax3
{ K9B_o,
sSiteURL = value; ?2zVWZ
} \ce (/I
`[p*qsp_
l)< '1dqe
public String getSFilePath() fNNkc[YTZI
{ [,Q(~Qb
return sFilePath; jFY6}WY)}7
} D::$YR ~R
RO+B/)~0<
19Xc0ez
public void setSFilePath(String value) m=<Tylv
{ #5-5N5-1
sFilePath = value; u@tJu'X
} 6:O3>'n
j}7as&
||a 5)D
public String getSFileName() y! he<4
{ r|wB& PGW
return sFileName; Q?-HU,RBO
} +ntrp='7O7
P9=L?t.
PXqLK3AE
public void setSFileName(String value) 3^AycwNBA
{ LW<DhMV
sFileName = value; 7^7Rk
} g+;)?N*j
,#3u.=IR[
{WQH
public int getNSplitter() V#["Z}
{ \]ouQR.t@\
return nSplitter; z/6/
} {U1 j@pKm
>Y=HP&A<
~SgW+sDFu
public void setNSplitter(int nCount) tgXIj5z
{ eSo/1D
nSplitter = nCount; [,[;'::=o4
} }6ObQa43
} Rp$t;=SMD
MF:]J
X_GR{z%
/* "9,z"k
**Utility.java /cHd&i,>
*/ [lZo'o
package NetFox; SQ!wq
^Yz.,!B[
5[l9`Cn&A
public class Utility { 5ws|4V
,_;+H*H>"
l^aG"")TH.
public Utility() RzCC>-
{ S-V)!6\cK
3Z=OUhn9
y3l3XLI*b
} i(P/=B
1cPm $=B
//线程睡眠 jY>|>]4X
public static void sleep(int nSecond) ?&$??r^i
{ w@RVg*`%7D
try{ zy\p,
Thread.sleep(nSecond); YoiM\gw
} V#8]io
catch(Exception e) "8MG[$Y
{ ^2Sa_.
e.printStackTrace (); <tkxE!xF`J
} AffVah2o:
} BzBij^h
%\6ns
//日志 @i'24Q[6
public static void log(String sMsg) #;FHyKx
{ F7$x5h@
System.err.println(sMsg); cpz'upVOZ
} :Awnj!KNCc
}YUUCq&
YT7,=k_
public static void log(int sMsg) E^uau=F
{ '}\{4Qst
System.err.println(sMsg); sute%6yM
} O%?TxzX;
} .Rt_j
!u~h.DrvZ
b]S4\BBT
/* ?^]29p_
**TestMethod.java &atT7m
*/ hnWo.5;$
package NetFox; S~jl%]
ga0>J_
7^$PauAv
public class TestMethod { XrR@cDNx{
;#c|ZnX
oFt]q =EU
public TestMethod() ?"MJ'u
{ ///xx/weblogic60b2_win.exe 6<0-GD}M
try{ +g36,!q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r,}U-S.w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yNp l0 d
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3/a$oO
fileFetch.start(); Co6ghH7T
} weQC9e~d{-
catch(Exception e){e.printStackTrace ();} I)$`@.
H':dLR
.5=Qfvi*
} (?MRbX]@
&1O[N*$e
Abr:UEG
public static void main(String[] args) 6GVj13Nr
{ Gy{C*m7Q
new TestMethod(); }'HJVB_
} :%GxU;<E{
} 5G.A\`u%
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