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)); hh8UKEM-
} huq6rA/i
for(int i=0;i<nEndPos.length-1;i++) '[juPI(!
{ S3J6P2P
nEndPos = nStartPos[i+1]; !^m5by
} NK4ven7/
nEndPos[nEndPos.length-1] = nFileLength; #g|j;{P
} C/cGr)|8%
} *e8V4P
q7)$WXe2LM
S"eKiS,z
//启动子线程 =}q4ked/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ivagS\Q
for(int i=0;i<nStartPos.length;i++) 1L9^N
{ +}Q4 g]M8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e6_.ID'3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /f6]XP\'`+
nStartPos,nEndPos,i); q2f/#"k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YT3QwN9
fileSplitterFetch.start(); @qe>ph[UA
} O.4"h4{'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Dr2h-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b1&{%.3[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b\+|g9Tm
nEndPos = " + nFileLength); AnyFg)a<
// fileSplitterFetch[nPos.length-1].start(); &6:,2W&s
M84LbgGM%
M\<!m^~
//等待子线程结束 UMX+h])#N
//int count = 0; pts}?
//是否结束while循环 000$ZsW?
boolean breakWhile = false; Xo*$|9[.
.kYzB.3@]
%F4Q|
while(!bStop) ]_=HC5"
{ "TV.$s$.
write_nPos(); C0fA3y72
Utility.sleep(500); XVLuhwi
breakWhile = true; kg61Dgu
c%U$qao=c+
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for(int i=0;i<nStartPos.length;i++) YH[_0!JY^
{ X or ,}. w
if(!fileSplitterFetch.bDownOver) Dsua13 hF
{ R] [M_ r
breakWhile = false; q7]WR(e
break; [.I,B tY+
} '?>eW2d
} VoyH:
if(breakWhile) '; dW'Uwc
break; 8k1r|s@d
8(KfX%
PVU"oz&T
//count++; oU@ljSD
//if(count>4) mce`1Tjw
// siteStop(); iy#OmI>j
} X@:fW @
g Oj5c
4d 3Znpf
System.err.println("文件下载结束！"); )ra66E
} xI4I1"/
catch(Exception e){e.printStackTrace ();} D+)=bPMe
} by U\I5
@NNLzqqY
`I>K?
//获得文件长度 U>+~.|'V9
public long getFileSize() 4ufLP DH
{ BXo|CITso
int nFileLength = -1; Doh|G:P]#
try{ 05KoxFO?
URL url = new URL(siteInfoBean.getSSiteURL()); 9f^PR|F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mVK9NK
httpConnection.setRequestProperty("User-Agent","NetFox"); bQy%$7UmX,
bVeTseAG
NN 6KLbC(
int responseCode=httpConnection.getResponseCode(); D'`"_
if(responseCode>=400) M#cr*%
{ uK:-g,;
processErrorCode(responseCode); NoO+xLHw8
return -2; //-2 represent access is error Dw=Z_+J
} daIL> c"
~{vdP=/WP
yJ8}*Gj&
String sHeader; +qj*P9
HQ3`:l
U('<iw,Yy
for(int i=1;;i++) 3Y{)(%I
{ 5g1M_8e'+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v$m[#&O^V?
//Utility.log(in.readLine()); aoDD&JE
sHeader=httpConnection.getHeaderFieldKey(i); %i-lx`U
if(sHeader!=null) N+M&d3H`
{ `SjD/vNE
if(sHeader.equals("Content-Length")) )6>|bmpU
{ WYC1rfd=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WjrMd#^
break; sk ?'^6Xh
} |R;l5ZKvV
} aGe(vQPi9
else U>_IYT
break; k9)u3
} G|-\T(&J
} #t@x6Vt
catch(IOException e){e.printStackTrace ();} )J+{oB[>b
catch(Exception e){e.printStackTrace ();} r)p2'+}pV
qggk:cN1
3_MS'&M
Utility.log(nFileLength); &'(a$S>v
{@V3?pG?p
;4G\]%c)E{
return nFileLength; #$=8g RZj
} a_{io`h3&
;T.s!B$Uu
t0bhXFaiE
//保存下载信息（文件指针位置） ;tp]^iB#
private void write_nPos() :4ja@~
{ OK-sT7But
try{ WQ[}&kY~
output = new DataOutputStream(new FileOutputStream(tmpFile)); !ww:O|0
output.writeInt(nStartPos.length); @VC .>
for(int i=0;i<nStartPos.length;i++) +9zJlL^A%
{ DB`$Ru@
// output.writeLong(nPos); n @&"+
output.writeLong(fileSplitterFetch.nStartPos); d&|z=%9xl
output.writeLong(fileSplitterFetch.nEndPos); _ktK+8*6`
} %j'G.*TD
output.close(); S jVsF1d_
} VYamskK[G:
catch(IOException e){e.printStackTrace ();} 1Xy8|OFc[
catch(Exception e){e.printStackTrace ();} NoCDY2 $
} rQ~\~g[tP
ietRr!$.
~u /aOd
//读取保存的下载信息（文件指针位置） d4Co^A&
private void read_nPos() <<=e9Lh
{ YV/>8*i
try{ erx5j\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4\LZD{
int nCount = input.readInt(); /&PKCtm&~
nStartPos = new long[nCount]; %G;0T;0L
nEndPos = new long[nCount]; 4_PCqEp)
for(int i=0;i<nStartPos.length;i++) BBHK
{ 8Y2xW`
nStartPos = input.readLong(); B7!<{i
nEndPos = input.readLong(); #D+7TWDwNt
} Z_H?WGO
input.close(); #`W=mN(+k
} @j O4EEe:
catch(IOException e){e.printStackTrace ();} M|\^UF2e
catch(Exception e){e.printStackTrace ();} ,E\h!/X
} lVPOYl%
w8O" =},
.VT;H1#
private void processErrorCode(int nErrorCode) \K}-I
{ ?4XnEDAm
System.err.println("Error Code : " + nErrorCode); 9O;cJ)tXY
} '|A|vCRCG
gtiEhCF2W
[r)eP({
//停止文件下载 N]NF\7(
public void siteStop() {esJ=FV\
{ +nZUL*Ut/
bStop = true; LL&ud_Y
for(int i=0;i<nStartPos.length;i++) *5_V*v6
fileSplitterFetch.splitterStop(); "~F3*lk#E
(n,u|}8Y
tz26=8
} ^/HW$8wEi
} lVz9k
//负责部分文件的抓取 YEv%C|l
**FileSplitterFetch.java o*">KqU`b
*/ iPq &Y*
package NetFox; : [q0S@
^W~p..DF
1B|8ZmFJj
import java.io.*; Mp~y0e
import java.net.*; ?38lHn`FyQ
>nzu],U
3iRA$C-p
public class FileSplitterFetch extends Thread { >I}9LyZt
k|xtrW`qo;
sIy
String sURL; //File URL :4:N f
long nStartPos; //File Snippet Start Position `:eU.
long nEndPos; //File Snippet End Position X&M4MuL
int nThreadID; //Thread's ID 'fx UV<K&
boolean bDownOver = false; //Downing is over sV/l5]b]
boolean bStop = false; //Stop identical u7fK1 ^O
FileAccessI fileAccessI = null; //File Access interface "9IYB)Js
?-MP_9!JK
UH? p]4Nz
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q8D&tJg
{ hA}~es=c
this.sURL = sURL; VA]e
this.nStartPos = nStart; !ErH~<f%K
this.nEndPos = nEnd; AH#4wPxF
nThreadID = id; ]5Qy
fileAccessI = new FileAccessI(sName,nStartPos);//定位 POAw M
} Os&n
HDVW0QaMu
ehNzDr\s
public void run() &Lm-()wb
{ ^03j8Pc-c
while(nStartPos < nEndPos && !bStop) K4Sk+ v
{ HOoPrB m
q[3x2sR
Bc7V)YK
try{ "{D6J809
URL url = new URL(sURL); ritBU:6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %FZ2xyI.
httpConnection.setRequestProperty("User-Agent","NetFox"); 1x)ZB~L
String sProperty = "bytes="+nStartPos+"-"; ({s6eqMhDd
httpConnection.setRequestProperty("RANGE",sProperty); *\}}Bv+9
Utility.log(sProperty); 80b;I|-T,
uo\ .7[1
hRC
InputStream input = httpConnection.getInputStream(); QaIjLc~W
//logResponseHead(httpConnection); *N'K/36;
P{OAV+cG
A4C+5R
byte[] b = new byte[1024]; : _e#
int nRead; Y;4!i?el
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6W[}$#w
{ XfPFo6
nStartPos += fileAccessI.write(b,0,nRead); kOOGw:/
//if(nThreadID == 1) fyTAou6hI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); in+}/mwfC
} zGKyN@o
F{06 _T
2H71~~ c
Utility.log("Thread " + nThreadID + " is over!"); 3@+b}9s8
bDownOver = true; ca i<,3H
//nPos = fileAccessI.write (b,0,nRead); >r`b_K
} L`f^y;Y.
catch(Exception e){e.printStackTrace ();} Y8M]Lwj
} CTX9zrY*T
} T|J9cgtS
^;!0j9"*:
O[tvR:Nh
//打印回应的头信息 vgY3L
public void logResponseHead(HttpURLConnection con) d->|EJP
{ .2d9?p3Y
for(int i=1;;i++) X%z }VA
{ 8fA_p}wp
String header=con.getHeaderFieldKey(i); !cKz7?w
if(header!=null) ? WJ> p
//responseHeaders.put(header,httpConnection.getHeaderField(header)); CYOI.#m2
Utility.log(header+" : "+con.getHeaderField(header)); P96pm6H_;
else X%yO5c\l2
break; V5+SWXZ
} l/;X?g5+
} mF` B#
n>@oBG)!
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public void splitterStop() r0p w_j
{ /Mb"V5S(W
bStop = true; OL4z%mDZi
} *s@Qtgu
&-(463
$w"$r$K9K
} Gy=B&boZ
Uj&W<'I
KWLbD#
/* F~A'X
**FileAccess.java u2 `b'R9
*//文件访问(定位，写) 7 |DHplI
package NetFox; [M+f-kl
import java.io.*; xf|mlHS+
%Uz(Vd#K
zYl#4O`=c
public class FileAccessI implements Serializable{ CI3XzH\IX*
}9nDo*A"}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5`f@>r?
RandomAccessFile oSavedFile; _X@v/sAy
long nPos; Tw +
bH"hX
6e7{Iy
public FileAccessI() throws IOException \U@rg4
{ b!M"VDjQ
this("",0); =4h+ M$2
} ;5@ t[r
mrX^2SR
]9\!;Bz^J
public FileAccessI(String sName,long nPos) throws IOException =J1rlnaaEL
{ ! !PYP'e
oSavedFile = new RandomAccessFile(sName,"rw"); \>Efd
this.nPos = nPos; Qt|c1@J
oSavedFile.seek(nPos); 52o x`t|
} PfkrOsV/m
q%ow/!\;
7'OtruJ
public synchronized int write(byte[] b,int nStart,int nLen) 02Ia2e.f
{ jM\*A#Jo5
int n = -1; Y@ZaJ@%9@
try{ >MPr=W%E
oSavedFile.write(b,nStart,nLen); C:G8c[
n = nLen; \e`~i@) ~Z
} o=nsy]'&
catch(IOException e) ^FnfJ:
{ f-r] |k
e.printStackTrace (); x"~~l
} RxQh2<?
'g9"Qv?0{`
`)QCn<
return n; Q);n<Z:X~
} (!:cen~|[
pC_O:f>vJ
hUm'8)OJ
} Rar"B*b;$
"]\+?
gkHNRAL
/* ,k G>?4
**SiteInfoBean.java E_zIg+(+
*/ U"50_O
package NetFox; 5y?-fT]X
[b$4Shx
Reu*Pe
public class SiteInfoBean { kHqztg
2./3 \n2
xai4pF-?
private String sSiteURL; //Site's URL 5 QO34t2
private String sFilePath; //Saved File's Path mLL340c#\
private String sFileName; //Saved File's Name |c`w'W?C6
private int nSplitter; //Count of Splited Downloading File 5pn)yk~
^H6<Km l/V
n>'Kp T9|
public SiteInfoBean() \.g\Zib )
{//nSplitter的缺省值为5 qL94SW;
//default value of nSplitter is 5 !`7B^RZ
this("","","",5); ''|#cEc)
} }E_#k]#*
EJ`T$JD
nB] >!q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 72veLB
{ )P|[r
sSiteURL= sURL; 3T&6opaF
sFilePath = sPath; "5A&_E }3
sFileName = sName; @ps1Dr4s
this.nSplitter = nSpiltter; C4NTh}6tT
P<fnLQ9
=!Q7}z1QI
} 'L{8@gqi
1$*%"5a
v)_nWu
public String getSSiteURL() cr;g5C V
{ )3h^Y=43
return sSiteURL; 1[]&(Pa
} 4hw@yTUo
{6oE0;2o'
BW,mwq
public void setSSiteURL(String value) _`#3f1F@[
{ )yo a
sSiteURL = value; ltFq/M
} *SO{\bu
MaD3[4@#
V i&*&"q
public String getSFilePath() ^_ojR4
{ ,<A$h3*
return sFilePath; j w* IO
} ^GBe)~MT
|+$%kJR=
^V|Oxp'7_
public void setSFilePath(String value) XW?b\!@ $
{ f7I{WfZ\P
sFilePath = value; ~y$!48o
} Ys!>+nL|
X w.p
hva2o`
public String getSFileName() Yhp]x
{ |7KeR-
return sFileName; KFZm`,+69
} *6U&Qy-M
5 |/9}^T
r 6eb}z!i
public void setSFileName(String value) Ix|~f1*%
{ AfC>Q!-w
sFileName = value; @/&b;s73
} I-agZag%
-VZRujl
VzJ5.mRQ
public int getNSplitter() k0Ek:MjJr
{ U}$DhA"r"
return nSplitter; RwVaZJe)l
} k-*Mzm]kb
g=T/_
]B=C|usJ
public void setNSplitter(int nCount) \(p{t
{ 1qi@uYDug
nSplitter = nCount; Ol$WpM
} vKoP|z=m
} gw _$
U1_&gy @y
&:=$wc
/* $mGvJ*9
**Utility.java vVT?h
*/ dGwszziuK
package NetFox; h.K(P+h
:c8n[+5
_GqS&JHSf
public class Utility { /HZumV?
D@X+{
r.0oxH']
public Utility() %i)B*9k
{ _~aG|mAj
G%u9+XV1#
`:M^8SYrL
} +\#Fd
PNSMcakD
//线程睡眠 6k?`:QK/sl
public static void sleep(int nSecond) ^%y`u1ab
{ (bn Zy0
try{ rsa&Oo D>
Thread.sleep(nSecond); A\te*G0:S
} zGc(Ef5`M6
catch(Exception e) vuz4qCQ
{ ^+?|Qfi
e.printStackTrace (); oN(-rWdhZ
} \Btk;ivg
} }gf}eH
cy~oPj]j
//日志 }fhHXGK.
public static void log(String sMsg) /48 =UK
{ -T/W:-M(
System.err.println(sMsg); ,ZI\dtl
} &d`^E6#
TA}UY7v
Hlj6$%.
public static void log(int sMsg) Sav`%0q?7a
{ 8 |h9sn;P
System.err.println(sMsg); bdc\
} k3@HI|
} nbdGt
%6 =\5>
zREJ#r
/* a}.Y!O&
**TestMethod.java E1>/R
*/ #A <1aQ
package NetFox; OKwOugi0
@Hr+/52B
W7G9Kx1Y
public class TestMethod { Gm=>!.p
5)lW
E;-qP)yU
public TestMethod() T'rjh"C&|
{ ///xx/weblogic60b2_win.exe "zV']A>4H
try{ K%,$ V,#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m7 XjP2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f?0s &Xo
SiteFileFetch fileFetch = new SiteFileFetch(bean); c>Z*/>~
fileFetch.start(); C*wdtEGq
} _dmL}t-
catch(Exception e){e.printStackTrace ();} ! sYf<
h-'wV${b
YQ,tt<CQ
} t9*=
m<fA|9 F#
.S vyj
public static void main(String[] args) -Z?Ck!00
{ 3&J&^O
new TestMethod(); $Qq_qTJu?G
} Hcl"T1N*
} 9A;6x$s
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