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)); Gd'^vqo<
} E2\)>YF{P
for(int i=0;i<nEndPos.length-1;i++) '[A>eC++
{ mB!81%f%|
nEndPos = nStartPos[i+1]; Pajr`gU
} A5nu`e9&
nEndPos[nEndPos.length-1] = nFileLength; \F<]l6E
} K|s+5>]W/[
} lxxK6;r~>
]])i"oew
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//启动子线程 PCFm@S@Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #}A!Bk
for(int i=0;i<nStartPos.length;i++) J"SAA0)@
{ }b0qrr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BgE]xm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b?Vu9!
nStartPos,nEndPos,i); Y@pa+~[{h3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ds-%\@p
fileSplitterFetch.start(); k|BEAdQ%M
} EKDv3aFQZ#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I=b#tUBh8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); myXp]=Sb?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Maq{H`
nEndPos = " + nFileLength); 9t)t-t#P;
// fileSplitterFetch[nPos.length-1].start(); @4&sL](q
CwT52+Jb
{UwJg
//等待子线程结束 t=U[ ;?
//int count = 0; AU >d1S.
//是否结束while循环 9aXm}
boolean breakWhile = false; , X|oCD
b^%4_[uRu
EGV@L#
while(!bStop) ebQYk$@
{ >w V$az
write_nPos(); >u6kT\|^C
Utility.sleep(500); J|K~a?&vN
breakWhile = true; D@0eYX4s
!Dun<\
j7i[z>:Y
for(int i=0;i<nStartPos.length;i++) n[{o~VN
{ PAqziq.
if(!fileSplitterFetch.bDownOver) B]kz3FF
{ dz7*a{
breakWhile = false; ]5} =r
break; .kBAUkL:
} 8^HMK$
} ^^)Pv#[3
if(breakWhile) 9@^/ON\O
break; kKCkjA:o##
&yYK%~}t[
id*UTY Tg
//count++; ^&.F!
//if(count>4) 4}l,|7_&I
// siteStop(); C~:aol i;
} {)`5*sd
6g<JPc
<Q%o}m4Kt
System.err.println("文件下载结束！"); ?X=9@m
} $3FFb#r
catch(Exception e){e.printStackTrace ();} ?Bk"3{hl
} eyy&JjVs
gBrIqM i5
B-Fu/n
//获得文件长度 n /rQ*hr
public long getFileSize() mWO=(}Fb\
{ BPC$ v\a
int nFileLength = -1; g*8sh
try{ )L^WD$"'Q
URL url = new URL(siteInfoBean.getSSiteURL()); :egSW2"5S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,Kdvt@vle
httpConnection.setRequestProperty("User-Agent","NetFox"); R`/nsou
F!.@1Fi1
om@` NW
int responseCode=httpConnection.getResponseCode(); ydBoZ3}
if(responseCode>=400) &?x^I{j
{ Inr ~9hz
processErrorCode(responseCode); v6iV#yz3(
return -2; //-2 represent access is error 'e0qdY`
} Mc{1Cdj
Th@L68
yzXwxi1#
String sHeader; lK}F>6^\
eZf-i1lJ
?2Bp^3ytJ
for(int i=1;;i++) !dmI}<@&k
{ ` R^[s56wp
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3A'd7FJ0G
//Utility.log(in.readLine()); EjvxfqPv
sHeader=httpConnection.getHeaderFieldKey(i); *}yW8i}36
if(sHeader!=null) 2W|j K
{ I:='LH,
if(sHeader.equals("Content-Length")) m3.d!~U\
{ 2,dGRf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [7L1y) I(
break; R1?g6. Mq
} ynDa4HB
} lHZf'P_Wx
else NjL,0Bp
break; -rU *)0PR
} v%B^\S3)
} T w/CJg
catch(IOException e){e.printStackTrace ();} nuXaZRH
catch(Exception e){e.printStackTrace ();} U4M!RdG
zYF'XB]4
d4gl V`%.
Utility.log(nFileLength); E]"ePdZZ/
1jQz%^~
X%39cXM C
return nFileLength; K2)),_,@5+
} XPb7gd"%W
u:fiil$
C9({7[k^%
//保存下载信息（文件指针位置） {8b6A~/
private void write_nPos() +-HaYB|p
{ `N2zeFG
try{ 5Ss=z
output = new DataOutputStream(new FileOutputStream(tmpFile)); .wYx_
output.writeInt(nStartPos.length); %z1WdiC
for(int i=0;i<nStartPos.length;i++) IOt!A
{ RM QlciG
// output.writeLong(nPos); [bE9Y;
output.writeLong(fileSplitterFetch.nStartPos); -s4qm)\
output.writeLong(fileSplitterFetch.nEndPos); zn@tLLX
} qH"e: wgL
output.close(); L +-B,466
} b\H~Ot[i
catch(IOException e){e.printStackTrace ();} Zj!S('hSY
catch(Exception e){e.printStackTrace ();} BQt!L1))
} TQYud'u/
mtmtOG_/=
~(G]-__B<
//读取保存的下载信息（文件指针位置） F|Jo|02
private void read_nPos() kXv -B-wOj
{ 4z?6[Cg<
try{ %p@A8'b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5ahAp];
int nCount = input.readInt(); RIb< 7
nStartPos = new long[nCount]; Rnun() plJ
nEndPos = new long[nCount]; p4|:u[:&
for(int i=0;i<nStartPos.length;i++) eDIjcZ
{ ld`oIEj!P_
nStartPos = input.readLong(); fs7JA=?:
nEndPos = input.readLong(); >.QD:_@:
} sd.:PE <
input.close(); ,SS@]9A&
} k45xtKS>d
catch(IOException e){e.printStackTrace ();} A10/"Ec<u
catch(Exception e){e.printStackTrace ();} zgqe@;{
} 3E:wyf)i"
Vh4z+JOC
,8EeSnI
private void processErrorCode(int nErrorCode) <86upS6
{ 1rT}mm/e;
System.err.println("Error Code : " + nErrorCode); '2v,!G]^
} ; #e-pkV
c:hOQZ
!dSY?1>U<
//停止文件下载 f4]nz:2
public void siteStop() ^MDBJ0 I.
{ ) Q]kUG#`
bStop = true; Pgs4/
for(int i=0;i<nStartPos.length;i++) v!K%\h2A
fileSplitterFetch.splitterStop(); \O72PC+
e#SNN-hKsJ
JzCfs<D
} .kvuI6H
} w%j 6zsTz
//负责部分文件的抓取 i#&]{]}Qv
**FileSplitterFetch.java vQYd!DSh
*/ F(}d|z@@
package NetFox; l'?/$?'e_Z
;sCX_`t0E
03AYW)"}M
import java.io.*; y! 7;Z~"
import java.net.*; 'I*F(4x
P[aB}<1f0
Vad(PS0
public class FileSplitterFetch extends Thread { 5|&Sg}_
J1P82=$,
86.!sQ8b
String sURL; //File URL D("['`{
long nStartPos; //File Snippet Start Position l,-smK69
long nEndPos; //File Snippet End Position enK4`+.7
int nThreadID; //Thread's ID UYGl
boolean bDownOver = false; //Downing is over 5qR76iH)/
boolean bStop = false; //Stop identical *cq#>rN
FileAccessI fileAccessI = null; //File Access interface 'xvV;bi
b]Oc6zR,,~
}a-ikFQ]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i#iY;R8
{ )6^b\`
this.sURL = sURL; Su6ZO'[)
this.nStartPos = nStart; v #IC
this.nEndPos = nEnd; H[fD >
nThreadID = id; u;J9aKD
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \d]&}`'4{f
} 9F ).i
FxD\F
uWvl<{2
public void run() **dGK_^T0
{ Nbuaw[[iz
while(nStartPos < nEndPos && !bStop) hFs0qPVY
{ DV]Kd 7
,TeDJ\k
_nOio?
try{ _Ev"/%
URL url = new URL(sURL); X*}S(9cg\i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &h8+-
httpConnection.setRequestProperty("User-Agent","NetFox"); M'R^?Jjb
String sProperty = "bytes="+nStartPos+"-"; cD-\fRBGK
httpConnection.setRequestProperty("RANGE",sProperty); Vy&F{T;$
Utility.log(sProperty); eW0:&*.vMj
C[_{ $j(J
(;V]3CtU*
InputStream input = httpConnection.getInputStream(); X7Cou6r
//logResponseHead(httpConnection); K;gm^
C}Ewi-
L)HuQVc g
byte[] b = new byte[1024]; L'z;*N3D
int nRead; 6EP5n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G2 xYa$&][
{ E!C~*l]wJx
nStartPos += fileAccessI.write(b,0,nRead); %ktU 51o
//if(nThreadID == 1) Y')in7g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Eki7bT@/
} W~Eq_J?I
nYTI\f/8v
=r:D]?8oC
Utility.log("Thread " + nThreadID + " is over!"); f+-w~cN
bDownOver = true; U_Emp[
//nPos = fileAccessI.write (b,0,nRead); RR*z3i`PP
} UIIunA9
catch(Exception e){e.printStackTrace ();} V92e#AR
} dD@T}^j *|
} sW@4r/F>:D
UOT~L4G
+twJHf_U
//打印回应的头信息 e8--qV#<
public void logResponseHead(HttpURLConnection con) ib;:*
{ -QI1>7sl
for(int i=1;;i++) nke[}Hqf
{ }eULcgRG
String header=con.getHeaderFieldKey(i); !@%m3)T8
if(header!=null) e J2wK3R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )TVyRYZ1
Utility.log(header+" : "+con.getHeaderField(header)); .#lQZo6$\|
else \/S?.P#L~
break; }7wQFKME
} ]C}z3hhk
} :X,1KR
g>T'R Vb
/'!F \ kz
public void splitterStop() +w%MwPC7`
{ po\QMe
bStop = true; cQS}pQyYN
} UTHGjE
~^KemwogPN
/8Ca8Ju
} f\2'/g}6a
&yp_wW-
y[.0L!C {
/* Cq}LKiu
**FileAccess.java "<txg%j\J
*//文件访问(定位，写) _N.ZpKVu
package NetFox; pU<->d;->
import java.io.*; I>C;$Lp]
y3))I\QT
"&77`R
public class FileAccessI implements Serializable{ US@ak4Y6Z
p`T7Y\\#!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .2Y"=|NdA
RandomAccessFile oSavedFile; cuW$%$F
long nPos; $*`fn{2
k%VV(P]sT
0 \&4?
public FileAccessI() throws IOException vb\UP&Ip
{ drNfFx2
this("",0); [gqV}Y"Md
} <eQS16
!xA;(<K[^
@]gP"Pp
public FileAccessI(String sName,long nPos) throws IOException !C&}e8M|eX
{ 7o'kdYJzo
oSavedFile = new RandomAccessFile(sName,"rw"); G0xk @SE
this.nPos = nPos; FgKDk!ci
oSavedFile.seek(nPos); p/4GOU5g
} $ [0
-YJ7ne]
4B^f"6'
public synchronized int write(byte[] b,int nStart,int nLen) 5 ,quM"
{ 6psK2d0
int n = -1; }gGcYRT
try{ "N D1$l
oSavedFile.write(b,nStart,nLen); vsRn\Y
n = nLen; P)7SK&]r;=
} ~eA7:dZLb
catch(IOException e) A@f`g[q
{ xCiY jl$
e.printStackTrace (); jaFBz&P/#
} NcwZ_*sqj
W7_X=>l
" q0lh
return n; j2k,)MHu!x
} QUH USDT
SB:-zQ5
kOs_]
} @m<xpel
3l-8TR
bmGIxBRq
/* o/)]z
**SiteInfoBean.java QZYD;&iY&
*/ ")i4w{_y
package NetFox; .?@$Rd2@W
j_j~BXhIS
l]uF!']f
public class SiteInfoBean { s1?N&t8c
}c:s+P+/
[yW0U:m
private String sSiteURL; //Site's URL xbvZ7g^
private String sFilePath; //Saved File's Path ?FA} ;?v
private String sFileName; //Saved File's Name #JWW ;M6F
private int nSplitter; //Count of Splited Downloading File BwEO2a{
~]O~a}]g(
Cevl#c5p>
public SiteInfoBean() g-bHf]'
{//nSplitter的缺省值为5 wC}anq>>
//default value of nSplitter is 5 &)T5V
this("","","",5); J)"2^?!&B
} /hQTV!\u
0h_9
ToTehVw
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9B{,q6
{ g\,pZ]0i
sSiteURL= sURL; >h(n8wTP
sFilePath = sPath; +ZQf$@+
sFileName = sName; L 1H!o!*
this.nSplitter = nSpiltter; pW2NrBq@w
b>er'U
U_K"JOZ
} xVfAlN37(
)R(kXz=M
wzwEYZN(q
public String getSSiteURL() cGIxE[n'
{ @4#q
return sSiteURL; 0r*E$|zZ
} .hzzoLI2
iV58 m
; $i{>mDT
public void setSSiteURL(String value) zogw1g&C
{ hs!a'E
sSiteURL = value; @!"w.@Y
} {P&{+`sov
"3(""0Q
TwH%P2)x
public String getSFilePath() SIYBMe
{ TWZ**S-
return sFilePath; _zvCc%
} K`{P/w
PzMJ^H{
m(i84~
public void setSFilePath(String value) 7l/.fSW
{ 7/&i'y
sFilePath = value; 3LN+gXmU
} @tGju\E"o
7jL+c~
#>iBu:\J
public String getSFileName() sEkfmB2J/
{ %UT5KYd!=N
return sFileName; ]V0V8fU|
} Kkcb'aDR
`<2k.aW4e8
1LYz X;H1
public void setSFileName(String value) )S@e&a|
{ Oi%\'biM
sFileName = value; f>!)y-7
} %A64AJZ
c%+/TO
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public int getNSplitter() `@TWZ%f6
{ Zgy~Y0Di
return nSplitter; !IF]P#
} gR1vUad7
.8e]-^Z
)Q= EmZbJz
public void setNSplitter(int nCount) _/V<iv
{ 9^;Cz>6s
nSplitter = nCount; G5*"P!@6
} |ecK~+
} ~wYGTm=(n
x3DUz
,2oFt\`.r
/* 3r^Ls[ey
**Utility.java S!WG|75B
*/ C0C2]xx{
package NetFox; bpP-wA^Hd
C2t]
X})5XYvA*
public class Utility { ^Gi9&fS,
[l44,!Z&
E$SYXe[,
public Utility() 2_T2?weD5
{ Db4(E*/pj!
t2x2_;a
Nm$Ba.Rg
} abMB-
@}; vl
//线程睡眠 h4p<n&)F
public static void sleep(int nSecond) '3<T~t
{ Z9wKjxu+
try{ Fi+8|/5
Thread.sleep(nSecond); ^AhV1rBB
} ~:FF"T>
catch(Exception e) (A(j.[4a
{ s.|OdC>U =
e.printStackTrace (); ly[j=vBV
} ^_\S)P2c
} =hRo#]{(K
%_Q+@9
//日志 Ec/&?|$
public static void log(String sMsg) .*}!XKp0j
{ A1Ru&fd!
System.err.println(sMsg); sqXwDy+.
} M$u.lI
{ 9:vq|
|$|B0mj
public static void log(int sMsg) "m#17J_
{ K_!R
System.err.println(sMsg); eI,'7u4q
} srlxp_^
} >Nam@,hm
A_e&#O
/a,"b8
/* 2# 72B
**TestMethod.java o|G'vMph
*/ $^:s)Yv
package NetFox; Qm_IU!b
WOg pDs
2dsXG$-W2
public class TestMethod { f9K+o-P.h
7D(Eo{ue
KvjsibI/Y
public TestMethod() S>Z07d6&
{ ///xx/weblogic60b2_win.exe gV}c4>v(
try{ !78P+i
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o75l&`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _V`F_C\\#
SiteFileFetch fileFetch = new SiteFileFetch(bean); z:^(#G{
fileFetch.start(); ZH)Jq^^RI
} ^HhV?Iqg
catch(Exception e){e.printStackTrace ();} n\ 'PNB
E3LEeXcLS
%W}YtDf\
} hbdB67,
Mfn^v:Q#
T)MX]T
public static void main(String[] args) Tw,|ZA4XH
{ 6E@TcN~,!
new TestMethod(); A$g'/QM
} j/t)=c
} T mK[^
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