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)); GH:Au
} dd$\Q
for(int i=0;i<nEndPos.length-1;i++) ]`UJwq
{ x{ZcF=4
nEndPos = nStartPos[i+1]; N 4,w
} u2U@Qrs2
nEndPos[nEndPos.length-1] = nFileLength; f Z\Ev%F
} fT'A{&h|U
} uYO?Rb&}
7 H<_ wW
oA42?I ^
//启动子线程 8SKDL[rN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w@oq.K
for(int i=0;i<nStartPos.length;i++) ;l?>+m@H
{ -G*u2i_*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v_G4:tY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gw5CU)r4$
nStartPos,nEndPos,i); S9xC> |<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r{Fu|aoa;5
fileSplitterFetch.start(); qLPI^g,
} } 10Dvt>+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wePMBL1P*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2poU\|H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", + ^~n09
nEndPos = " + nFileLength); iAXx`>}m
// fileSplitterFetch[nPos.length-1].start(); A 7TP1
3HfT9
2@A7i<p
//等待子线程结束 ;N4mR6
//int count = 0; wV(_=LF
//是否结束while循环 dn5T7a~
boolean breakWhile = false; 9Uk9TG5
/=-E`%R}!
Q2k\8i
while(!bStop) @c.QrKSaD
{ ,sJ{2,]~
write_nPos(); tc# rL
Utility.sleep(500); guf+AVPno
breakWhile = true; ~%GUc ~
5a_K|(~3I
U>:p`@
for(int i=0;i<nStartPos.length;i++) A}oR,$D-
{ *9*I:Uh57
if(!fileSplitterFetch.bDownOver) B|!YGfL
{ 47t^{WrT
breakWhile = false; |pJ.73
break; [.6uw=;o
} }*+ca>K
} U8.DPRa
if(breakWhile) 6:h!gY
break; KL -8Aj~
gE8>5_R|
vO"AJ`_
//count++; AoTL)',
//if(count>4) Ho\z^w+T`
// siteStop(); v'Lckw@G4
} =I*"vwc?
_<5> E
EI/_=.d
System.err.println("文件下载结束！"); g:OVAA
} 0WYVt"|;}c
catch(Exception e){e.printStackTrace ();} 6idYz"P %
} NEK;'"~
WlG/7$
Zb}=?fcL;@
//获得文件长度 n1!u aUC
public long getFileSize() znu?x|mV
{ mEE/Olh W
int nFileLength = -1; jIuE1ve
try{ k deJB-
URL url = new URL(siteInfoBean.getSSiteURL()); !5p01]7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7(wY4T
httpConnection.setRequestProperty("User-Agent","NetFox"); EP{y?+E2
0R*!o\y
(\SxG\`
int responseCode=httpConnection.getResponseCode(); <4Ujk8Zj
if(responseCode>=400) vY.p~3q :)
{ ~/gqXT">
processErrorCode(responseCode); @0t,vye
return -2; //-2 represent access is error JJ[J'xl@
} kbOo;<X9A
VE{t]>*-u
K4oLb"gB1
String sHeader; 79S=n,O
;l~gA|A
$L;7SY?
for(int i=1;;i++) 5w{_WR6,
{ ]k>S0
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [?]s((A~B
//Utility.log(in.readLine()); wn|Sdp
sHeader=httpConnection.getHeaderFieldKey(i); Q2iu}~
if(sHeader!=null) Rrk3EL
{ -S9$C*t
if(sHeader.equals("Content-Length")) xNl_Q8Z?R^
{ D(L%fK`+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %hOe `2#$
break; &{l?j>|TM
} (}c}=V
} _%"/I96'
else -CxaOZG
break; .PxtcC.K
} n802!d+Tn
} 7FfzMs[\e
catch(IOException e){e.printStackTrace ();} /z~;.jRg
catch(Exception e){e.printStackTrace ();} Tpkm\_
OSsdB%bIu`
Q- j+#NGc
Utility.log(nFileLength); -,}f6*
u'P@3'P
+FyG{1?<
return nFileLength; R%54!f0 %
} Hz+edMUL
H@MUzV
oGXT,38*
//保存下载信息（文件指针位置） e|xRK?aVBu
private void write_nPos() Q<Utwk?nL
{ 5f}wQ
try{ qI KVu_
output = new DataOutputStream(new FileOutputStream(tmpFile)); s_p?3bKu
output.writeInt(nStartPos.length); NcFHvK
for(int i=0;i<nStartPos.length;i++) m<TKy_C`
{ bIwt#:v
// output.writeLong(nPos); P(qUx9
output.writeLong(fileSplitterFetch.nStartPos); LXfDXXF
output.writeLong(fileSplitterFetch.nEndPos); u9sffX5x[J
} o'r?^ *W
output.close(); -*+7-9A I
} lHr?sMt
catch(IOException e){e.printStackTrace ();} /ey}#SHm,
catch(Exception e){e.printStackTrace ();} |)yO]pB:
} ;/ WtO2
>`\~=ivrD
62a{Ggs{
//读取保存的下载信息（文件指针位置） '}]w=2Lf
private void read_nPos() mI?AI7DqK
{ ZShRE"`
try{ t"JfqD E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); So,EPB+
int nCount = input.readInt(); OG/R6k.
nStartPos = new long[nCount]; $)z(4Ev
nEndPos = new long[nCount]; K^?/
for(int i=0;i<nStartPos.length;i++) |*jnJWH4:
{ ~b\bpu
nStartPos = input.readLong(); 3S +.]v>
nEndPos = input.readLong(); RE7 I"
} 7n}J}8Y*U2
input.close(); 2NqlE
} oTT/;~I
catch(IOException e){e.printStackTrace ();} S'vrO}yU
catch(Exception e){e.printStackTrace ();} )0~zL} )?
} gz Qc
!&?(ty^F
@My-O@C>
private void processErrorCode(int nErrorCode) op/|&H'
{ -h8A<
System.err.println("Error Code : " + nErrorCode); @6(4}&sEdm
} Ftu4 V*lD
*8t_$<'dQ
0x[v)k9"0
//停止文件下载 -7$7TD`'7
public void siteStop() DMsxHAE1
{ 7_ZfV? .
bStop = true; b-yfBO
for(int i=0;i<nStartPos.length;i++) C.Y]PdYyj
fileSplitterFetch.splitterStop(); kk )9!7
F@)wi0
M7BJ$fA0E
} ^4h/6^b0c
} <jY"+@rF
//负责部分文件的抓取 bK<'J=#1
**FileSplitterFetch.java Mb"i}Yt{
*/ gW$X8ECX
package NetFox; `o)rAD^e
%N=-i]+Id
oj;Rh!O
import java.io.*; fiES6VL
import java.net.*; C`%cPl
OpW4@le_r
R>BnUIu
public class FileSplitterFetch extends Thread { -5\hZ!!J2
^fQ ]>/u
q`{crY30
String sURL; //File URL LlrUJ-uC7
long nStartPos; //File Snippet Start Position 2dFC{US'
long nEndPos; //File Snippet End Position 48Vmz
int nThreadID; //Thread's ID z~# .Ey
boolean bDownOver = false; //Downing is over _2R;@[f2
boolean bStop = false; //Stop identical 4'RyD<K\
FileAccessI fileAccessI = null; //File Access interface GNgPf"}K
|B./5 ,nSS
BRi\&&<4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0P3^#j
{ 6X$]d^)h{
this.sURL = sURL; Oc}4`?oy<O
this.nStartPos = nStart; h2QoBGL5
this.nEndPos = nEnd; [:&4Tp*C
nThreadID = id; WA\ P`'lg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ocotO
} 5RrzRAxq
[u`v'*0d
\L($;8`\
public void run() %scSp&X
{ }4Ef31X8q
while(nStartPos < nEndPos && !bStop) "eA4JL\%)
{ q@1b{q#C5
rF'_YYpr>
z'z_6]5
try{ BGh1hyJ8d
URL url = new URL(sURL); \vjIw{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3WHj|ENW
httpConnection.setRequestProperty("User-Agent","NetFox"); x\z*iv
String sProperty = "bytes="+nStartPos+"-"; )*}2L_5]
httpConnection.setRequestProperty("RANGE",sProperty); (P%{Tab
Utility.log(sProperty); 7k.=_Tl
@eU;oRVc{
Oi+9kk e
InputStream input = httpConnection.getInputStream(); dUegHBw_`R
//logResponseHead(httpConnection); b=amd*
x|g>Zd/n
jNd."[IrO
byte[] b = new byte[1024]; cv})^E$x
int nRead; &66-0d+Sh
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !YYI{BJ7:N
{ pN|BtrN{
nStartPos += fileAccessI.write(b,0,nRead); =4+Wx8ZeW
//if(nThreadID == 1) 7jPPN
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #;4<dDVy
} D"UCe7
l6]:Zcd0
5 YjqN
Utility.log("Thread " + nThreadID + " is over!"); %#kml{I
bDownOver = true; (1Q G]1q
//nPos = fileAccessI.write (b,0,nRead); Osz:23(p
} $o2H#"
catch(Exception e){e.printStackTrace ();} 6b`3AAGU"
} X` r~cc
} |>X5@
A/:^l%y,GZ
1-JdQs6
//打印回应的头信息 ^Y[.-MJt+
public void logResponseHead(HttpURLConnection con) qtlXDgppO
{ `>'%!E9G
for(int i=1;;i++) }rK9M$2]u
{ U?]}K S;6
String header=con.getHeaderFieldKey(i); _-mSK/Z
if(header!=null) <~s{&cL!%#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *f<+yF{=A
Utility.log(header+" : "+con.getHeaderField(header)); .S4c<pMap
else Y=0D[o8
break; .xG3`YH
} ~nLE?>x|Z
} %+gK5aVab
ul@G{N{L
lqdil l\
public void splitterStop() gkkT<hEV=
{ p8gm=
bStop = true; g}\G@7Q
} xb8S)zO]Q
5AFy6Ab
1j4tR#L
} f0Wbc\L[
qrdA4S
m^?a/
/* *DBm"{q%&k
**FileAccess.java at<N?r
*//文件访问(定位，写) E^'f'\m
package NetFox; e"g=A=S
import java.io.*; B L^?1x
5=cS5q@
*BdKQ/Dk
public class FileAccessI implements Serializable{ f%ThS42
y@GqAN'DK[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L?h'^*F H}
RandomAccessFile oSavedFile; }(MI}o}
long nPos; vU(uu:U9
nev@ykP6
V7~tIhuJH
public FileAccessI() throws IOException =o_Ua^mr
{ ;YGCsLT<xt
this("",0); RV@'$`Q
} ;-]' OiS;
)SjhOvm
-2DvKW$
public FileAccessI(String sName,long nPos) throws IOException +wPXDN#R
{ ;zF3e&e(
oSavedFile = new RandomAccessFile(sName,"rw"); JJE?!Yvc
this.nPos = nPos; <A~a|A-QFR
oSavedFile.seek(nPos); r3OR7f[
} vIzREu|5
esh7*,7-z*
Gn?NY}.S
public synchronized int write(byte[] b,int nStart,int nLen) rm}%C(C{J
{ Fi!BXngbd
int n = -1; ue8"_N
try{ -w'_Q"o2
oSavedFile.write(b,nStart,nLen); 2oBT _o%/J
n = nLen; Sj(5xa[
} ]0dj##5tJ
catch(IOException e) ]wxjd l
{ _ZMAlC*$G
e.printStackTrace (); .dwy+BzS
} e #!YdXSx
GBg~NkC7.
f$y`tT %o
return n; NpPuh9e{
} j-$F@p_2F
`>1XL2
\img
} 'r0kX||
NB^+Hcb$
ojva~mnFf
/* +`RQ^9
**SiteInfoBean.java 3u,CI!
*/ \>]C
package NetFox; 4it^-M
Ea,L04K
x9!3i{_
public class SiteInfoBean { {r>iUgg
j0wpaIp
|d)*,O4s
private String sSiteURL; //Site's URL :HiAjaA1pg
private String sFilePath; //Saved File's Path 9\ulS2d
private String sFileName; //Saved File's Name d!P3<:+R[
private int nSplitter; //Count of Splited Downloading File 7ciSIJ
;}>g/lw
Gv(?u
public SiteInfoBean() P Y&(ObC
{//nSplitter的缺省值为5 iVSN>APe
//default value of nSplitter is 5 UE\Z]t!
this("","","",5); RW4,j&)
} %a\L^w)Xn
my]t[%Q{
`uh+d
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) , RKl
{ E;MelK<8(
sSiteURL= sURL; })F.Tjf*
sFilePath = sPath; f`W)Z$fN5
sFileName = sName; )Vf!U"
this.nSplitter = nSpiltter; G4;5$YGG
a\l?7Jr
*}h#'+
} Q94Lq~?YF
2 ":W^P
3 BQZ[%0@
public String getSSiteURL() DQI b57j
{ JYw_Z*L=m
return sSiteURL; b4?]/Uy+/
} ^:cc3wt'3[
I<+i87=
EA``G8Vn>
public void setSSiteURL(String value) +bDBc?HZ{$
{ 8\VP)<<
sSiteURL = value; ZJf:a}=h
} Z#NEa.]
sS{!z@\Lf
M 8NWQ^Y
public String getSFilePath() 4.e0k<]N`
{ xP7#`S6W
return sFilePath; 4Q17vCC*n
} v$)ZoM6E
:B7dxE9[r
L/c`t7
public void setSFilePath(String value) /6{P ?)]pE
{ vq` M]1]FO
sFilePath = value; +(U;+6 b
} csjCXT=Ve
,CxIA^
90Bn}@t=Q
public String getSFileName() *8Kx y@
{ vdaG?+_o
return sFileName; s9rKXY',:l
} #V$h?`qhwr
up!54}qy
8G )O,F7z
public void setSFileName(String value) Ud& '*,
{ ^61;0
sFileName = value; wx*03(|j;
} /<VR-yr
SH6+'7
5ktFL<^5T
public int getNSplitter() JUCp#[q
{ &dky_H
return nSplitter; 6o)RsxN eu
} )#l&BV5
)]tf|Mbu
S;^'Ek"Z.
public void setNSplitter(int nCount) @%"r69\
{ LsxRK5
nSplitter = nCount; {\vcwMUzZ
} L_sDbAT~<
} 7e:eL5f>~
E_D0Nm%n
hw({>cH\
/* uk9!rE"
**Utility.java 7 -S?U~s
*/ +z|@K=d#|
package NetFox; e'A1%g)
#h}a
;_S DW
public class Utility { yu}yON
hem>@Bp'V
n{I1ZlEeh
public Utility() ,L=lg,lH^
{ Yb\d(k$h
B|K^:LUk9
MxDqp;
} ]@!3os,CNF
WBWIHv{j
//线程睡眠 1hY%ZsjC
public static void sleep(int nSecond) &~:+2
{ d7G DIYH<
try{ }R!t/8K
Thread.sleep(nSecond); 4Opf[3]
} \0n<6^y
catch(Exception e) &Jd_@F#J
{ dUL*~%2I
e.printStackTrace (); FQ>y2n=<d
} 9]vy#a#
} ^'p!#\T;H
M#k$[w}=
//日志 (#BOcx5J]
public static void log(String sMsg) dpvEY(Ds
{ }g& KT!r
System.err.println(sMsg); `=lo.c
} BtrMv6
@E4ya$A)F
Q`!^EyRA:^
public static void log(int sMsg) ~t1?oJ
{ DQ@M?~1hp
System.err.println(sMsg); 2f6BZ8H+Z
} BvS!P8
} NJCSo(O
&2nICAN[
@JPz|
/* sI6I5
**TestMethod.java 7+;.Q
*/ ~^PNMZk
package NetFox; i&q_h>ZTg
8g {;o7
'p[*2J"K4
public class TestMethod { z.|[g$F
OF0v0Y/a
jx}7/
public TestMethod() XAN.Plk
{ ///xx/weblogic60b2_win.exe {:#c1d2@8
try{ N;a'`l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WfHa
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |]~],
SiteFileFetch fileFetch = new SiteFileFetch(bean); vVZ+u4y
fileFetch.start(); mV0u:ws
} 7x]q>Y8T
catch(Exception e){e.printStackTrace ();} -jzoGzC3
U]W"
{55f{5y3 c
} y@SI)&D
klMpiy
KGGnypx`
public static void main(String[] args) 6tGF
{ yg6o#;
new TestMethod(); kjDmwa+91T
} Nza@6nI"
} oIniy{
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