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)); H#E
} 6ApW+/
for(int i=0;i<nEndPos.length-1;i++) bS&'oWy*B
{ ;} gvBI2e
nEndPos = nStartPos[i+1]; blid* @-
} $&qB,>5=X
nEndPos[nEndPos.length-1] = nFileLength; 1i_~ZzX8
} N$/{f2iC
} A%"XNk
s Ce7ni
)"WImf:*
//启动子线程 T5z %X:VD(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; BtBo%t&
for(int i=0;i<nStartPos.length;i++) V{HZ/p_Y
{ 8q)2)p
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `-\4Dx1!q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z%`} `(
nStartPos,nEndPos,i); mppBc-#EYr
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~r]ZD)
fileSplitterFetch.start(); )3.udx
} 6O"Vy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'M_8U0k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <eO 7b6_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F@ZG| &
nEndPos = " + nFileLength); a,d\<mx
// fileSplitterFetch[nPos.length-1].start(); Ki^m&P
BNyDEFd
nv{ou[vQ
//等待子线程结束 L -b~#
//int count = 0; $B~a*zZ7
//是否结束while循环 CUnZ}@?d
boolean breakWhile = false; H5,{Z
z Rz#0
8!3+Obj
while(!bStop) c500:OSB
{ To]WCFp6@
write_nPos(); j6/ 3p|E
Utility.sleep(500); {AO3o<-h
breakWhile = true; |QAmN>7U
f4/!iiS}r
}.NR+:0
for(int i=0;i<nStartPos.length;i++) ZA2y
{ kC01s
if(!fileSplitterFetch.bDownOver) $B}(5Da
{ Wxjk}&+pVa
breakWhile = false; A!Ng@r
break; vD:.1,72
} YCh!D dy
} bLCrh(<
if(breakWhile) &VR<'^>
break; *X*D, VY
+P~zn=
O~">-'f
//count++; klT6?'S
//if(count>4) PgB=<#9
// siteStop(); 2YuaPq/
} 2EG"xA5%
bkmX@+Pe
)09_CC!a
System.err.println("文件下载结束！"); ksu:RJ-
} `WWf?g
catch(Exception e){e.printStackTrace ();} 4yQ4lU,r
} VY=~cVkzS
GY@Np^>[a
K._1sOw'"Y
//获得文件长度 &|9mM=^
public long getFileSize() d^ipf*aLC
{ A |NX"
int nFileLength = -1; OTN"XKa$
try{ tI.(+-q
URL url = new URL(siteInfoBean.getSSiteURL()); g|)e3q{M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bCd! ap+#
httpConnection.setRequestProperty("User-Agent","NetFox"); Qyt6+xL
8uyVx9C0
Sl:\5]'yJ
int responseCode=httpConnection.getResponseCode(); -/#3U{O
if(responseCode>=400) pm5Yc@D
{ qbqJ1^!6R
processErrorCode(responseCode); 8 Sl[&
return -2; //-2 represent access is error ai#EFo+#
} /RX7AXXB
Y)BKRS~
5kC#uk
String sHeader; +8Peh9"
0AR4/5.
S_ nTp)
for(int i=1;;i++) [0/?(i|
{ oS_'@u.5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); uKpl+>
//Utility.log(in.readLine()); 86R}G/>>e
sHeader=httpConnection.getHeaderFieldKey(i); q69a-5q
if(sHeader!=null) eZ}FKg%2[
{ G<Lm}
if(sHeader.equals("Content-Length")) xs.[]>nQN
{ kwWO1=ikz@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _AVCh)Zb
break; S:Yo9~
} (9Hc`gd)p
} @3VL _g:
else =%2 E|/
break; [jAhw>
} cv#H
} #GWQ]r?
catch(IOException e){e.printStackTrace ();} yv$MQ~]
catch(Exception e){e.printStackTrace ();} KxJJ?WyM
$?*+P``
jLb3{}0
Utility.log(nFileLength); >z[d~
tvFJ^5
T,WWQm
return nFileLength; )h+JX8K)l
} "T~Ps$
r9b`3yr=
K''b)v X4
//保存下载信息（文件指针位置） azE>uEsE
private void write_nPos() &<tji8Dj
{ zQ)[re)
try{ K =7(=Y{
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1$xt=*.u|
output.writeInt(nStartPos.length); *qz]vUb/0
for(int i=0;i<nStartPos.length;i++) {qOSs,+=L
{ G1| Tu"
// output.writeLong(nPos); &qe:|M
output.writeLong(fileSplitterFetch.nStartPos); JpSS[pOg
output.writeLong(fileSplitterFetch.nEndPos); }$$b6G
} @B&hR} 4
output.close(); ISq^V
} y{v*iH<
catch(IOException e){e.printStackTrace ();} =#y&xWxL
catch(Exception e){e.printStackTrace ();} ]}'WNy6c&x
} 72v 9S T
!knYD}Rxd
%>JqwMK
//读取保存的下载信息（文件指针位置） v- {kPc=:#
private void read_nPos() `P# h?tZ
{ k]f73r
try{ OW #pBeX99
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); '}!dRpx
int nCount = input.readInt(); F." L{g
nStartPos = new long[nCount]; $&a`zffG
nEndPos = new long[nCount]; kV(?u_ R
for(int i=0;i<nStartPos.length;i++) SKcAZC
{ q=[0`--cd
nStartPos = input.readLong(); 0K#dWc}"a
nEndPos = input.readLong(); iqOd]H]v
} rH-_L&
input.close(); F,lQj7
} lzwr]J%|?
catch(IOException e){e.printStackTrace ();} 9ykmz (
catch(Exception e){e.printStackTrace ();} ]+@b=J2b
} lJU[9)Q_
%/sf#8^m
ryPz?Aw(4
private void processErrorCode(int nErrorCode) bgEUG
{ y-Z*qR?
System.err.println("Error Code : " + nErrorCode); M4DRG%21
} L[O+9Yh
-2Ub'*qK
C w$y
//停止文件下载 K-#Rm%J+Wy
public void siteStop() lI&0 V5
{ T1e}WJbFE
bStop = true; DrB=
for(int i=0;i<nStartPos.length;i++) &}P62&
fileSplitterFetch.splitterStop(); !{ )H
M)|}Vn;!
,:;_j<g`e
} xQ$*K]VP
} w>m/c1
//负责部分文件的抓取 yWX:`*GV
**FileSplitterFetch.java NB,iC [e
*/ W=G[hT5L{
package NetFox; KH[%HN5v
{ >4exyu6
$/pd[H[{
import java.io.*; lYJ]W[!
import java.net.*; Y> 7/>x6
^WUF3Q**OU
Ct.Q)p-wn
public class FileSplitterFetch extends Thread { J#JZ^59lOS
AQ-PY
IcaF4#
String sURL; //File URL ,?`$~8
long nStartPos; //File Snippet Start Position .CmwR$u&
long nEndPos; //File Snippet End Position .Mm8\].
int nThreadID; //Thread's ID M6g!bK2l
boolean bDownOver = false; //Downing is over 2^Y1S?g.
boolean bStop = false; //Stop identical 'rz*mR8
FileAccessI fileAccessI = null; //File Access interface y]@_DL#J=
n:;2Z
ZT|E1[Q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~+4OG 0
{ r5rK>
this.sURL = sURL; }_Jai4O
this.nStartPos = nStart; Ig S.U
this.nEndPos = nEnd; O":x$>'t
nThreadID = id; :~`E@`/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LqU]&AAh
} +F`! Jt
Z*kg= hs^
.YLg^JfZ
public void run() Jzfzy0$
{ &)`A4bf%
while(nStartPos < nEndPos && !bStop) 3Vt-]DGX
{ PUucYc
scrNnO[3j
#~ /-n&#
try{ )5e}Id
URL url = new URL(sURL); T!J\Dm-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f<y""0L9
httpConnection.setRequestProperty("User-Agent","NetFox"); ,qaIdw[
String sProperty = "bytes="+nStartPos+"-"; m]&d TZV
httpConnection.setRequestProperty("RANGE",sProperty); >JnEhVRQJ9
Utility.log(sProperty); {?#g*QF|^
.F> cZ,
fr:RiOPn
InputStream input = httpConnection.getInputStream(); Yuh t<:`
//logResponseHead(httpConnection); 5 {'%trDEy
y37n~~%
]D(%Ku,O%
byte[] b = new byte[1024]; HnU}Lhjzj
int nRead; |-2,k#|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l|\Q~ D!o
{ _DH,$evS%
nStartPos += fileAccessI.write(b,0,nRead); .D>%-
//if(nThreadID == 1) \@tt$ m%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f{ENSUtCrR
} ESb
%*:-4K
n,n]V$HFGh
Utility.log("Thread " + nThreadID + " is over!"); 7GE.>h5
bDownOver = true; a^~l[HSF
//nPos = fileAccessI.write (b,0,nRead); MW`q*J`Yo
} M~P}80I
catch(Exception e){e.printStackTrace ();} V#5BZU-
} ~Kt.%K5lgt
} \e( h6,@
+&Sf$t 1
?%;)> :3N
//打印回应的头信息 8n1Sy7K!;
public void logResponseHead(HttpURLConnection con) He&dVP
{ ]<TgBo|
for(int i=1;;i++) UB(Q &U_
{ |67<h5Q1
String header=con.getHeaderFieldKey(i); aBol9`6
if(header!=null) u["Pg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O@?? NF6G
Utility.log(header+" : "+con.getHeaderField(header)); l[rIjyL@
else EPdR-dC^wE
break; yO$]9
} TzerAX^
} uFG]8pj2V1
3'*SSZmnOB
m9xO& @#vx
public void splitterStop() O`~T:N|D
{ 36.L1!d)pE
bStop = true; =U3!D;XP
} k`kmmb>
"-(yZigQ
[%z~0\lu8
} `<C)oF\~f
k}Ahvlq)
|.)dOk,o
/* f; >DM
**FileAccess.java :] {+3A
*//文件访问(定位，写) wD}[XE?S
package NetFox; }.MJVB3
import java.io.*; o= N=W
~kw[Aw3?D\
'Pr(7^
public class FileAccessI implements Serializable{ (&+ ~hW5d
gmy_ZVU'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 IP/ zFbc
RandomAccessFile oSavedFile; Rr(,i%fu
long nPos; ~vBmW_j
B,,f$h!
gx@b|rj;
public FileAccessI() throws IOException 8H3|^J
{ :Uj+iYE8Z8
this("",0); W UDQb5k
} jsfyNl?6
w/E4wp
J{\S+O2,*
public FileAccessI(String sName,long nPos) throws IOException DRj\i6-v
{ (/tbe@<
oSavedFile = new RandomAccessFile(sName,"rw"); ~z%K9YcyU
this.nPos = nPos; BTgL:
oSavedFile.seek(nPos); @T>)fKCg
} \oLRNr[F
b78'yM&
L:%; Fx2
public synchronized int write(byte[] b,int nStart,int nLen) $kvF]|<bu
{ Vb|DNl@
int n = -1; ld$LG6[PA
try{ Quc9lL
oSavedFile.write(b,nStart,nLen); ,8cw jS2E
n = nLen; D />REC^
} K zKHC
catch(IOException e) b.Z K1
{ e*Sv}4e=.
e.printStackTrace (); &ZClv"6
} {&,a)h7&
!7P 1%/
fp|b@
return n; d&PXJ
} Cd"O'<^Sb
JrQ*.lJj
G*3O5m
} ?)'j;1_=E3
#ZeZs31
DNq=|?qn]
/* 6rF[eb
**SiteInfoBean.java `oXUVr
*/ G@BF<e{
package NetFox; Fpzps!(;=
"ALR)s,1,
Z,! w.TYo
public class SiteInfoBean { &d[&8V5S
u B~/W
JyvXNV,
private String sSiteURL; //Site's URL l;b5v]~
private String sFilePath; //Saved File's Path ,3!l'|0jJ
private String sFileName; //Saved File's Name O}*[@uv/
private int nSplitter; //Count of Splited Downloading File xT#j-T
%j^[%&pT
@G~T&6E!
public SiteInfoBean() My&h{Qk
{//nSplitter的缺省值为5 d_-{-@
//default value of nSplitter is 5 .^X IZ
this("","","",5); 'dDd9
} ~^UQw?;
m%X~EwFc.
v1 d]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) K%Vl:2#F
{ ICTl{|i ]
sSiteURL= sURL; ]<WKi=
sFilePath = sPath; 8Tyf#`'I
sFileName = sName; K!lGo3n]
this.nSplitter = nSpiltter; A=Q"IdK
/9/=]
3&/5!zOg)
} (B.J8`h }
vA10'Gx'
b6 &`]O;%
public String getSSiteURL() C6Ap 4
{ -^Baxkq(YM
return sSiteURL; \=?f4*4|/
} Klzsr,
@f-0OX$*
u0^GB9q
public void setSSiteURL(String value) D[x0sly
{ l Ztq_* Fl
sSiteURL = value; (@vu/yN
} n"Ot'1yr
'3 xvQFg
=1!wep"
public String getSFilePath() ~T|?!zML
{ JM0'V0z
return sFilePath; WJ9Jj69
} {*bXO8vi((
l}&egq DC
n9B1NM5 \
public void setSFilePath(String value) jFZJ #'CNS
{ %u-l6<w#R
sFilePath = value; nzmv>s&UW
} X<9jBj/t
{n2mh%I
!G.)%+Z
public String getSFileName() Y.Na9&-(
{ {e/Qs|a R
return sFileName; '-p<E"#4Z
} ]O3[Te
yk5-@qo
X!2/cgU7
public void setSFileName(String value) U-6b><
{ )zkk%mE/IM
sFileName = value; <v&>&;>3
} R;,+0r^i
7rw}q~CE5
7Co }4
public int getNSplitter() {aqceg
{ ( ?3 )l
return nSplitter; I9h?Z&n5
} 3rhH0{
V7.xKmB
u* G|TF
public void setNSplitter(int nCount) 2u4aCfIx
{ *`YR-+0
nSplitter = nCount; Y-hGHnh]'
} a02@CsH
} ZC'(^liAp
BaIH7JLZ8
sNZ{OD+
/* JeU|e$I4>
**Utility.java WUkx v*
*/ 5K|1Y#X
package NetFox; Q7zg i
ABvB1[s#
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public class Utility { ':lADUt
MYFRrcu;
RR<92R
public Utility() glbU\K> >
{ zpx
^P >; %
fn>MOD!l
} ,.6Hh'^65^
r'wam]1Z
//线程睡眠 ]fg?)z-Z
public static void sleep(int nSecond) [H$rdh[+
{ *[t@j*al
try{ Q9=X|
Thread.sleep(nSecond); 'kPc`)\
} {]]qd!,
catch(Exception e) \^orl9
{ DfgqB3U[
e.printStackTrace (); ^5x\cR
} xH!{;i
} Wg9q_Ql
v>CAA"LH
//日志 4zX@TI>j
public static void log(String sMsg) zL$$G,
{ z)I.^
System.err.println(sMsg); `O ?61YUQH
} AI}29L3C
fT9$0:eO
PB*mD7"
public static void log(int sMsg) /co^swz
{ CKeT%3
System.err.println(sMsg); gF,9Kv~
} Xn^gxOPM
} ZG+8kt!w
eS{lr4-]
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/* {{w5F2b((%
**TestMethod.java me"}1REa
*/ %/NB263Db
package NetFox; }w^Hm3Y^&
PMC5qQ%x
ya8MjGo
public class TestMethod { W;en7v;#I}
=S7Xj`/
PRcW}"m]Qg
public TestMethod() %H Pwu &
{ ///xx/weblogic60b2_win.exe ~fbFA?g3
try{ ^u`1W^>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *f{\ze@5=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4/e|N#1`;[
SiteFileFetch fileFetch = new SiteFileFetch(bean); MgkeD
fileFetch.start(); qT}<D`\
} tJ`tXO
catch(Exception e){e.printStackTrace ();} w6(E$:#d
aGY R:jR$
?o307r
} yXyL,R
Wv!#B$J~U
[S;ceORx
public static void main(String[] args) w;+x g
{ 1'ts>6b
new TestMethod(); +QpgG4h
} I~ Q2jg2
} BnJpC<xm
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