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)); Nj>6TD81u
} (TT=i
for(int i=0;i<nEndPos.length-1;i++) ^~H}N$W"-q
{ &42]#B"*
nEndPos = nStartPos[i+1]; !vwio!
} .==D?#bn
nEndPos[nEndPos.length-1] = nFileLength; 6iU&9Z<%
} 8o5[tl ?w
} b&rBWp0#
ps{4_V-3u
zq};{~u(
//启动子线程 ~~/,2^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; RAO+<m
for(int i=0;i<nStartPos.length;i++) ETHcZ
{ $wUYK%.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =*\.zr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xOTvrX
nStartPos,nEndPos,i); _KH91$iW8m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,R{&x7
fileSplitterFetch.start(); Sb`[+i'`
} 6^b)Q(Edut
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 64/ZfXD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *O_fw 0jV
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \L*%?~
nEndPos = " + nFileLength); _w\9 \<%
// fileSplitterFetch[nPos.length-1].start(); 6eSo.@*l
SxRJ{m~
j[r}!;O
//等待子线程结束 kk=n&M
//int count = 0; ZsP^<
//是否结束while循环 gQ\.|'%
boolean breakWhile = false; GeR#B;{
?Q]&;5o
Z@Rm^g]o
while(!bStop) .RxTz9(
{ !PA:#]J
write_nPos(); 6F(z6_<
Utility.sleep(500); ^N={4'G)
breakWhile = true; o[!'JUxZ
geG0F}oC!
Xw4Eti._D
for(int i=0;i<nStartPos.length;i++) *?m)VvR>|
{ ^Hn}\5
if(!fileSplitterFetch.bDownOver) 'NtI bS
{ R (f:UC
breakWhile = false; %ztZ#h~g
break; S\:^#Yi`
} [K4cxqlfk
} &ivU4rEG
if(breakWhile) >#G%2Vp
break; |Rfj 0+
G+c&e:ip<
xv]z>4@z,
//count++; [7@blU
//if(count>4) E/:U,u{
// siteStop(); |#yu
} %],BgLhS.
)O[8 D
rp@:i _]
System.err.println("文件下载结束！"); |nQfgl=V
} 3WwS+6R
catch(Exception e){e.printStackTrace ();} Dge#e
} >6C\T@{lJ
!BoGSI
\g34YY^L3
//获得文件长度 @D9O<x
public long getFileSize() p cLKE ZK
{ 0!\gK<,z
int nFileLength = -1; \lK?f]qJq
try{ L~&S<5?
URL url = new URL(siteInfoBean.getSSiteURL()); ,Q"'q0hM=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k[x-O?$O@
httpConnection.setRequestProperty("User-Agent","NetFox"); K&[0`sH!
`:C1Wo^<
n5QO'Jr%[
int responseCode=httpConnection.getResponseCode(); x]7:MG$
if(responseCode>=400) Vl^x_gs#_]
{ &;$uU
processErrorCode(responseCode); 2U./ Yfk\
return -2; //-2 represent access is error =zn'0g,J4
} dy6zrgxygP
2? E;(]dQ
1|sem(t
String sHeader; VD.TosVeWo
MXSD8]je
g(&cq
for(int i=1;;i++) H>+/k-n-
{ t=7Gfv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vC,FE )'
//Utility.log(in.readLine()); (U'n1s/X
sHeader=httpConnection.getHeaderFieldKey(i); aqSOC(jU
if(sHeader!=null) oRbWqN`F.
{ g]f<k2
if(sHeader.equals("Content-Length")) Szzj9K
{ ;<i u*a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |Y"XxM9
break; Pim
} j([b)k=
} gV]4R"/
else IgbuMEfL
break; 'fn}I0Vc
} [],[LkS
} 'ON/WKJr|W
catch(IOException e){e.printStackTrace ();} le5@WG/x
catch(Exception e){e.printStackTrace ();} ;W{z"L;nX
5j`sJvq
-)-:rRx-
Utility.log(nFileLength); T.#_v#oM
xI<l1@
'wPX.h?
return nFileLength; #.Dl1L/
} k)knyEUi
r8(oTx
3Y P! B=
//保存下载信息（文件指针位置） 7T[L5-g
private void write_nPos() OXLB{|hH80
{ 2]fTDKh
try{ <~|n}&
output = new DataOutputStream(new FileOutputStream(tmpFile)); #s~ITG#H
output.writeInt(nStartPos.length); @6ckB (
for(int i=0;i<nStartPos.length;i++) )nHMXZ>Td
{ lZwjrU| _
// output.writeLong(nPos); C 9%bD
output.writeLong(fileSplitterFetch.nStartPos); 7Ydqg&
output.writeLong(fileSplitterFetch.nEndPos); Ow-ejo
} lz=DGm
output.close(); pKLcg"{[F
} Ps0Cc_
catch(IOException e){e.printStackTrace ();} `pbCPa{Y
catch(Exception e){e.printStackTrace ();} b#7nt ?`7p
} (B` NnL$
1<9d[N*
ky !ZJR
//读取保存的下载信息（文件指针位置） K14.!m
private void read_nPos() :/6:&7s
{ bN?*p($/
try{ L@MCB-@V
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lsV>sW4]Z
int nCount = input.readInt(); uhq6dhhR
nStartPos = new long[nCount]; 9ZOQNN<ex
nEndPos = new long[nCount]; _ (b4|hJ'
for(int i=0;i<nStartPos.length;i++) kYS#P(1
{ /;_$:`|/
nStartPos = input.readLong(); =)y$&Ydj
nEndPos = input.readLong(); g,E)F90
} jYU0zGpj
input.close(); .NdsKhg b
} T72Li"00
catch(IOException e){e.printStackTrace ();} ~a=]w#-KD
catch(Exception e){e.printStackTrace ();} AYNz {9
} o<b
Il/`#b@h
fCa lR7!
private void processErrorCode(int nErrorCode) ft8
{ ++2a xRl
System.err.println("Error Code : " + nErrorCode); [GknE#p
} UHY)+6qt]
2;:]Q.g
(QFZM"G
//停止文件下载 i_Lu
public void siteStop() GF9iK|i/
{ V13^SVM
bStop = true; ~i-n_7+
for(int i=0;i<nStartPos.length;i++) Q]/g=Nn ^~
fileSplitterFetch.splitterStop(); P,S!Z&!
k5&}bj-
#5;4O{
} SFWS<H(IN
} 5UL5C:3R9
//负责部分文件的抓取 `iuQ.I
**FileSplitterFetch.java [9EL[}
*/ fpNq
package NetFox; 2wU,k(F_
S@\&^1;4Hv
un6W|{4]
import java.io.*; {w>ofyqfp&
import java.net.*; CNiJuj`
5'Mw{`
*[nS*D\:
public class FileSplitterFetch extends Thread { _z^&zuO
YbVZK4
mznE Cy
String sURL; //File URL ;XY#Jl>tg
long nStartPos; //File Snippet Start Position I<lkociUCG
long nEndPos; //File Snippet End Position #r&yH^-
int nThreadID; //Thread's ID \XY2s&"
boolean bDownOver = false; //Downing is over MMRO@MdfV
boolean bStop = false; //Stop identical #I yM`YB0
FileAccessI fileAccessI = null; //File Access interface Ejf>QIB
ku v<
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException DKQQZ`PF
{ c1%ki%J#
this.sURL = sURL; a;7gy419<p
this.nStartPos = nStart; blV'-Al
this.nEndPos = nEnd; d#,
nThreadID = id; tG,xG&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YcaLc_pUx
} _#UhXXD
^oHK.x#{
]N'4q}<5o
public void run() "^pF2JI
{ 5tbi};
while(nStartPos < nEndPos && !bStop) bir tA{q
{ )Z?\9'6e4
Re\V<\$J
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try{ o AS 'Z|
URL url = new URL(sURL); 53^1;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AQBr{^inH|
httpConnection.setRequestProperty("User-Agent","NetFox"); #5kg3OO
String sProperty = "bytes="+nStartPos+"-"; 5o~AUo{
httpConnection.setRequestProperty("RANGE",sProperty); h1_KZ[X
Utility.log(sProperty); jK=-L#hz
eR1]<Z$W\
=uR[Jewa
InputStream input = httpConnection.getInputStream(); a67NWH
//logResponseHead(httpConnection); doe u`
( (mNB]sy
[VB\T|$
byte[] b = new byte[1024]; 6v-2(Y
int nRead; `_e1LEH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) - zEQ/6
{ W$Z""
nStartPos += fileAccessI.write(b,0,nRead); g|3FJA/
//if(nThreadID == 1) zQ eXN7$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -/qu."9(B
} mK7egAo
^nL_*+V`f
wmS:*U2sc
Utility.log("Thread " + nThreadID + " is over!"); $VE=sS.
bDownOver = true; _1Iw"K49Qx
//nPos = fileAccessI.write (b,0,nRead); nIP*yb}5
} Z"<tEOs/En
catch(Exception e){e.printStackTrace ();} oY%NDTVN
} Jo ]8?U(^
} _q\w9gN
,e>N9\*
(OK;*ZH+T@
//打印回应的头信息 G0h7MO%x
public void logResponseHead(HttpURLConnection con) blB00
{ n47v5.Wn
for(int i=1;;i++) b{d@:"
{ t?kbN\,
String header=con.getHeaderFieldKey(i); n|iO)L\9aB
if(header!=null) ~); 7D'[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yX8$LOjE
Utility.log(header+" : "+con.getHeaderField(header)); 5SY(:!
else VJ(#FA2
break; w+owx(mN@
} =:=uV0jX\
} Ih0kdi
AUAJMS!m
$'VFb=?XrK
public void splitterStop() wg,w;Gle
{ <[GkhPfZ
bStop = true; wN!5[N"
} !n/"39KT
S-6%mYf
S(*SUH
} )b AcU
Hlq#X:DCn
gg%OOvaj5
/* O}#h^AU-BS
**FileAccess.java ] Vbv64M3
*//文件访问(定位，写) F.JvMy3
package NetFox; S2fBZ=V8
import java.io.*; "h}miVArS
}%9A+w}o
/g!', r,
public class FileAccessI implements Serializable{ !N1DJd
p9)'nU'\t
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +K%4jIm
RandomAccessFile oSavedFile; LY^pmak
long nPos; Hh8)d/D
~O}LAzGb
v [ 4J0
public FileAccessI() throws IOException @nS+!t{
{ + >oA@z
this("",0); 7,2bR
} Ie~#k[X
J_A5,K*r|
I vQ]-A}N
public FileAccessI(String sName,long nPos) throws IOException zj^Ys`nl
{ (TV ye4Z
oSavedFile = new RandomAccessFile(sName,"rw"); =)3tVH&
this.nPos = nPos; 3X&}{M:Qo
oSavedFile.seek(nPos); 3R[5prE<
} Q0_UBm^f
jdGoPa\
IOsitMOX:
public synchronized int write(byte[] b,int nStart,int nLen) +idj,J|
{ *s9 +
int n = -1; s^b2H !~
try{ /gKX%`ZF/r
oSavedFile.write(b,nStart,nLen); !(soMv
n = nLen; ["\Y-6"l
} iii2nmiK
catch(IOException e) Y\len
{ bCF"4KXK
e.printStackTrace (); [g:ZIl4p\P
} q]Cmaf(
@<tkwu
%_!YonRY|X
return n; SAt{At
} fKMbOqU_
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nTweQ
} #s)Wzv%OX
FaC;vuSpy
M3350
/* S3u>a\
**SiteInfoBean.java '8v^.gZ
*/ ;aip1Df
package NetFox; kckWBL
~ FW@
?1Lzbou
public class SiteInfoBean { 1O0o18'
r(IQ)\GR
'dp3>4
private String sSiteURL; //Site's URL vl<W`)'
private String sFilePath; //Saved File's Path i*'6"
private String sFileName; //Saved File's Name 1;R1Fj&
private int nSplitter; //Count of Splited Downloading File V6Y:l9
|~Hlv^6H
w^?uBeqR
public SiteInfoBean() T<"Hh.h
{//nSplitter的缺省值为5 C{<qc,!4
//default value of nSplitter is 5 s('<ms
this("","","",5); SNB>
} & Me%ZM0
q/[)Z @&(
QXnL(z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6u`E{$
{ b/='M`D}#G
sSiteURL= sURL; %l!Gt"\xm
sFilePath = sPath; f:gXXigY,
sFileName = sName; xioL6^(Qk,
this.nSplitter = nSpiltter; K)c`G_%G
|T~C($9
C3^QNhv
} 5 iUT#
1CFTQB>
o/bmS57
public String getSSiteURL() {%ZD^YSA
{ qh!2dj
return sSiteURL; Np=IZnpt
} mdW8RsR
V8w!yc
1H{M0e
public void setSSiteURL(String value) 6H,n?[zTt
{ L,L>cmpM
sSiteURL = value; J fFOU!F\
} 7KOM,FWKe
vq|o}6Et
T> cvV
public String getSFilePath() {k=H5<FV
{ p}%T`e=Z9
return sFilePath; mrR~[533j
} p.kJNPO\@
#E%0 o
(5y+g?9d;
public void setSFilePath(String value) -NW7ncB|
{ Sdl1k+u
sFilePath = value; u6{=Z:
} ,*SoV~
[hE0 9W
j]\3>.
public String getSFileName() Z?yMy zT
{ v`ckvl)(C
return sFileName; Z<6XB{Nh\
} [m3[plwe
1'wwwxe7
rcUXYJCh-
public void setSFileName(String value) O`_!G`E
{ zWYm*c"n\
sFileName = value; zyyt`
} $Cw> z^}u
!e?g"5r{Bv
dGf:0xE"
public int getNSplitter() D7.|UG?G
{ .}W#YN$
return nSplitter; JX%B_eUlAs
} SXfuPM
{//;GC*
x9Veg4Z7
public void setNSplitter(int nCount) /g}2QmvH
{ C'mYR3?m;
nSplitter = nCount; 5}d"nx
} gPs%v`y)*D
} vovc,4}
#p@8m_g
$\BRX\6(-
/* kk_$j_0
**Utility.java W<<{}'Db/#
*/ d7 )&Z:
package NetFox; tW4|\-E"s4
EHk(\1!V
cNX,%
public class Utility { OU&eswW
7#K%Bo2pG
wLyQ <[$
public Utility() K?[*9Q'\
{ Ml`tDt|;
R[Y]B$XO
zs!}P
} Id`?yt
|_q:0qo
//线程睡眠 X=O}k&
public static void sleep(int nSecond) <xOv0B
{ gd~# uR\
try{ zrD];DP
Thread.sleep(nSecond); &?\'Z~B4
} > <cK
catch(Exception e) 1<Fh aK
{ hs'J'~a
e.printStackTrace (); wfr+-
} g wM~W
} kkfwICBI
Q2[@yRY/z
//日志 N\ nr
public static void log(String sMsg) So &c\Ff
{ T8|aFoHCK
System.err.println(sMsg); +3B^e%`NPm
} "YLH]9"=
*LnY}#
?@W=bJ8{
public static void log(int sMsg) ,0ZkE}<=w
{ \wW'Hk=
System.err.println(sMsg); (ATvH_Z
} Y@WCp
} ?U~}uG^
q}Wd`>VDR
5r1{l%?
/* 2p3ep,
**TestMethod.java " jefB6k9h
*/ -cW`qWbd
package NetFox; xsjJ8>G
O&=40"Dr
> "G HLi
public class TestMethod { Wl3jbupu _
y>+xdD0+
_y~H#r9:
public TestMethod() .eQIU$Kw!O
{ ///xx/weblogic60b2_win.exe @bu5{b+8
try{ 4 I}xygV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qucw%hJr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $.Fti-5
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0:K4,
fileFetch.start(); "X/cG9Lw
} ^fj):n5/
catch(Exception e){e.printStackTrace ();} C^Jf&a
rTJv>Jjld
q3.L6M
} ,BuN]9#
7ky$9+~
d~[^D<5,D
public static void main(String[] args) *ml&}9
{ J7.}2
new TestMethod(); *h ~Y=#`8*
} VKa-
} =}@m$g
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