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)); >9H@|[C
} X[](Kj^`<
for(int i=0;i<nEndPos.length-1;i++) nXA\|c0
{ F%d\~Vj
nEndPos = nStartPos[i+1]; VsK>6S\T
} a|4~NL
nEndPos[nEndPos.length-1] = nFileLength; C3'rtY.
} R@iUCT^$
} =IU*}>#
\.uc06
wQ+8\ s=
//启动子线程 lFSe?X^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p|+B3
for(int i=0;i<nStartPos.length;i++) $t~@xCi]S
{ 0d^Z uTN
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l;A,0,i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p\p\q(S">
nStartPos,nEndPos,i); l?8M p$M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r?/A?DMe
fileSplitterFetch.start(); /) 4GSC}Gg
} 1f'Hif*r_X
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wg`AZ=t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); tK(g-u0N`(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^|!I+
nEndPos = " + nFileLength); c{+AJ8
// fileSplitterFetch[nPos.length-1].start(); }8-\A7T
? "/ fPV-
Iu@y(wyg
//等待子线程结束 w Y
//int count = 0; SqA J-_~
//是否结束while循环 A{eLl
boolean breakWhile = false; S8d8%R~1=h
"=. t 36#
20RXK1So
while(!bStop) V'Kgdj
{ ;%C'FV e]
write_nPos(); ~PWSo%W8
Utility.sleep(500); =sJ _yq0#R
breakWhile = true; wC_l@7t
lbdTQ6R
+=q)
for(int i=0;i<nStartPos.length;i++) G!N{NCq
{ iIT8H\e
if(!fileSplitterFetch.bDownOver) (>4aibA'P
{ A>`945|
breakWhile = false; Kv'n:z7Md
break; fWc|gq
} \c v?^AI
} 57a2^
if(breakWhile) &3F}6W6A
break; IQ<MyB(
.nu @ o40
aI(7nJ=R
//count++; !Z!g:II /
//if(count>4) Migd(uw'
// siteStop(); <ljI;xE
} D\w h;r
`\`>0hlu
n79QJl/
System.err.println("文件下载结束！"); 9SlNq05G7
} 7]xm2CHx5
catch(Exception e){e.printStackTrace ();} T9)nQ[
} FLg*R/
FGO[ |]7IN
S##1GOO
//获得文件长度 >Rvx[`|O!m
public long getFileSize() ;6@r-r
{ 0]QRsVz+
int nFileLength = -1; |@,|F:h<M
try{ HEL!GC>#
URL url = new URL(siteInfoBean.getSSiteURL()); aQ^umrj@?9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T=hhoGn
httpConnection.setRequestProperty("User-Agent","NetFox"); ~\x:<)
(,^*So/
6sIL.S~c)
int responseCode=httpConnection.getResponseCode(); #&v/icz$
if(responseCode>=400) `%+ mO88o
{ ,+`61J3W
processErrorCode(responseCode); #;n+YM">:
return -2; //-2 represent access is error 4Mk-2 Dx
} hcVJBK
:o:e,WKxb
^F?&|clM/
String sHeader; cvwhSdZu8
eC5$#,HiC
Z/rP"|EuQ
for(int i=1;;i++) | mu+9
{ dU\%Cq-G)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ARcv;H 5
//Utility.log(in.readLine()); eEhr140
sHeader=httpConnection.getHeaderFieldKey(i); 7~#:>OjW
if(sHeader!=null) q+B&orp
{ ,=?{("+
if(sHeader.equals("Content-Length")) +[SgO}sF
{ @EE."T9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8M@BG8
break; XZw6Xtn
} x `V;Y]7'
} ;3_l@dP"
else 4v[~r1!V
break; ''\;z<v
} 8kP3+
} ?\8?%Qk
catch(IOException e){e.printStackTrace ();} UT}i0I9
catch(Exception e){e.printStackTrace ();} wP"dZagpj
EGl^!.'
"UwH\T4I
Utility.log(nFileLength); czlFr|O;
,lCgQ0}<
xkOpa,=FI
return nFileLength; 5>AX*]c
} T{wuj[Q#:
u&wiGwF[
)Ud-}* g
//保存下载信息（文件指针位置） L@JOGCYy
private void write_nPos() W2uOR{ '?
{ #07gd#j4
try{ :!zl^J;
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5q"ON)x
output.writeInt(nStartPos.length); DWdW,xG
for(int i=0;i<nStartPos.length;i++) _)]CzBRq\6
{ !x'/9^i~v
// output.writeLong(nPos); Z,iHy3`
output.writeLong(fileSplitterFetch.nStartPos); d#2$!z#
output.writeLong(fileSplitterFetch.nEndPos); ')GSAY7
} m|OO,gR
output.close(); q&:=<+2"
} 2Pc%fuC
catch(IOException e){e.printStackTrace ();} / g 2b
catch(Exception e){e.printStackTrace ();} }MUn/ [x
} JI vo_7{
NWxUn.Gy9
O9:U8$*
//读取保存的下载信息（文件指针位置） ?ve#} \
private void read_nPos() NY?;erX
{ dK>7fy;mv
try{ |F#1C9]P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }`+B=h-dW
int nCount = input.readInt(); 'w1YFdW
nStartPos = new long[nCount]; 1{P'7IEj
nEndPos = new long[nCount]; ? R>h `
for(int i=0;i<nStartPos.length;i++) {/pm<k=
{ d|4}obCt
nStartPos = input.readLong(); "W(Q%1!Wi
nEndPos = input.readLong(); *}8t{ F@k
} [LRLJ_~g5
input.close(); M`S0u~#tI
} .H,xle
catch(IOException e){e.printStackTrace ();} 8zMu7,E
catch(Exception e){e.printStackTrace ();} IT$25ZF
} \}]!)}G
O`vTnrY
Zkf0p9h\
private void processErrorCode(int nErrorCode) $[yFsA6
{ `7H4Y&E
System.err.println("Error Code : " + nErrorCode); yeHDa+}
} VWO9=A*Y|
o: ;"w"G
0 Us5
//停止文件下载 Qqlup
public void siteStop() ":_vK}5
{ 2=_gf
bStop = true; "9n3VX)
for(int i=0;i<nStartPos.length;i++) $HJwb-I
fileSplitterFetch.splitterStop(); R"K#7{p9
GaSPJt
c*@G_rb
} QD%L0;j
} im @h -A]0
//负责部分文件的抓取 LQjsOo
**FileSplitterFetch.java yBI'djL~>
*/ T*KMksjxm`
package NetFox; Z> r^SWL
5#K4bA
%AQIGBcgL
import java.io.*; $1v&azM.
import java.net.*; H#ncM~y*
L5,NP5RC
P@FHnh3}Z$
public class FileSplitterFetch extends Thread { DY^;EZ!hb
AFAAuFE"
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String sURL; //File URL ` Jdb;
long nStartPos; //File Snippet Start Position ~s5SZK*
long nEndPos; //File Snippet End Position RSo&(Uv
int nThreadID; //Thread's ID 9:M` j
boolean bDownOver = false; //Downing is over ^_m9KA
boolean bStop = false; //Stop identical YY!Rz[/
FileAccessI fileAccessI = null; //File Access interface ]KmO$4
"&3h2(#%
~ yX2\i"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException KGg3 !jY
{ +>PX&F
this.sURL = sURL; 6:~v4W!k
this.nStartPos = nStart; )P+7PhE{J
this.nEndPos = nEnd; !50[z:
nThreadID = id; IC7M$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [Vma^B$7Vj
} ,{mCf^
?Ec7" hK
)Eo)t>
public void run() K>{T_){
{ Gn&4V}F
while(nStartPos < nEndPos && !bStop) !@v7Zu43,
{ @mfEKU!
^f(@gS}?
V 0rZz
try{ 4F{70"a
URL url = new URL(sURL); GP#aya
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8e(\%bX
httpConnection.setRequestProperty("User-Agent","NetFox"); 0vw4?>Jf@
String sProperty = "bytes="+nStartPos+"-"; VTH> o>g
httpConnection.setRequestProperty("RANGE",sProperty); >qF CB\(
Utility.log(sProperty); ^- d%r
-(=eM3o-9m
3p'I5,}
InputStream input = httpConnection.getInputStream(); ^N)R=tl
//logResponseHead(httpConnection); gdQvp=v]
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1Yn +<I
byte[] b = new byte[1024]; Pjc Tx +
int nRead; H/37)&$E(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) J_4!2v!6e
{ FIsyiSY<j
nStartPos += fileAccessI.write(b,0,nRead); kbe-1 <72
//if(nThreadID == 1) {Ja!~N;3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1|jt"Hz
} )<tI!I][j
KGFv"u{
;4pYK@9w_
Utility.log("Thread " + nThreadID + " is over!"); q0zr E5
bDownOver = true; G2T|RT$_K
//nPos = fileAccessI.write (b,0,nRead); n~V ]Z
} uu>Pkfo
catch(Exception e){e.printStackTrace ();} @8I4[TE
} uwy:t!(j
} <Pi|J-Y
_+E5T*dk
ilqy/fL#
//打印回应的头信息 (:>,u*x%
public void logResponseHead(HttpURLConnection con) av|g}xnj
{ ?snp8W-WB
for(int i=1;;i++) 4v{o
{ Ob<{G"
String header=con.getHeaderFieldKey(i); :Nz2z[W$
if(header!=null) =7m)sxj]w
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~o~!+`@q
Utility.log(header+" : "+con.getHeaderField(header)); pWJFz-
else V: TM]
break; L bmawi^
} JVSA&c%3
} ybKWOp:O
lE(a%'36
W~7A+=&
public void splitterStop() LF& z
{ @y\XR
bStop = true; i=oU;7~zK
} 5lUF7:A>#
%#xaA'? [
!'9Feoez
} 9~/J35
<"my^
R[hzMU}KB
/* 4J/}]Dr5
**FileAccess.java 7\s"o&G
*//文件访问(定位，写) ?b>,9A.Z
package NetFox; IHv[v*4:
import java.io.*; 9^#c| 0T
7%|~>
}%{LJ}\Px
public class FileAccessI implements Serializable{ ?q{,R"
LQRQA[^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 F7EKoDt
RandomAccessFile oSavedFile; `3WFjU5a
long nPos; WGZ9B^A
kr9*,E9cv
%|q>pin2
public FileAccessI() throws IOException sl`s_$J
{ ~ls[Sl@
this("",0); 0vD7v
} S]Mw#O|
T^k7o^N>
9Hb6nm
public FileAccessI(String sName,long nPos) throws IOException tne ST.
{ !C3MFm{B
oSavedFile = new RandomAccessFile(sName,"rw"); |es?;s'
this.nPos = nPos; PuA9X[=
oSavedFile.seek(nPos); K1+)4!}%U
} TE7nJ gm
L>aLqQ3
YSic-6z0Ms
public synchronized int write(byte[] b,int nStart,int nLen) lJ}_G>GJ
{ DpvI[r//'*
int n = -1; L(|N[#
try{ e]$}-i@#
oSavedFile.write(b,nStart,nLen); 1Vrh4g.l
n = nLen; QLvHQtzwX
} qzKdQ&vO
catch(IOException e) 2db3I:;E
{ ZQ%'`q\c
e.printStackTrace (); ~-_kM
} Gi?/C&1T
V)~.~2$
QSdHm
return n; 7e|s wJ>4
} [S9K6%w_!
-$cmG4
.ps-4eXF
} yW1)vD7
7XTkX"zKj
8hOk{xs8
/* _/-jX
**SiteInfoBean.java 4U+xb>
*/ 7vrl'^1
package NetFox; |Mup8(gCk
[B#R94
'MUv5Th
public class SiteInfoBean { 4ew" %Cs*
N~goI#4
(_mnB W
private String sSiteURL; //Site's URL N`5,\TR2f
private String sFilePath; //Saved File's Path )NXmn95
private String sFileName; //Saved File's Name tl,.fjZn
private int nSplitter; //Count of Splited Downloading File =[cS0Sy
(|:M&Cna]
vNV/eB8#S
public SiteInfoBean() `.~N4+SP
{//nSplitter的缺省值为5 Rg\z<wPBG
//default value of nSplitter is 5 fk6%XO
this("","","",5); A+ZK4]xb
} la0BiLzb]
([T>.s
"d#Y}@*~o
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #~}nFY.
{ &C,'x4c"
sSiteURL= sURL; ZM!CaR
sFilePath = sPath; 9kN}c<o
sFileName = sName; B(LWdap~
this.nSplitter = nSpiltter; ~:kZgUP_f
S;3R S;
/YP{,#p
} sJ;g$TB
vj'wm}/
\qdHX
public String getSSiteURL() s C%&cRQD
{ 42_`+Vt]d7
return sSiteURL; Neq+16*u
} D/Z6C&/I
X$ 0?j1
u]<,,
public void setSSiteURL(String value) 5nv#+ap1 "
{ C%$edEi
sSiteURL = value; :)wy.r;N
} bf ]f=;.+
#^lL5=
Vwg|K|
public String getSFilePath() L[oui,}_
{ D.B.7-_8
return sFilePath; s@&`f{
} 'y;EhOwj,
sT3^hY7
~ -4{B
public void setSFilePath(String value) j"ThEx0
{ lGPUIoUo
sFilePath = value; Bn=by{i
} f2Klt6"9
1n >X[! 8x
AF;)#T<
public String getSFileName() rn/ /%
{ <r.)hT"0
return sFileName; bR*-Ht+wd
} KyVQh8
ocqU=^ta
g`{;(/M+
public void setSFileName(String value) 8{wwd:6
{ 9oRy)_5Z(=
sFileName = value; /[a~3^Gs^
} q.KG^=10
6Z>FTz_
A>vBQN
public int getNSplitter() UldXYtGe
{ 2 Wt> Mi
return nSplitter; "9ZID-~]
} N=4G=0 `ke
MW! srTQ_
j`JMeCG=Ee
public void setNSplitter(int nCount) V, Z|tB^
{ iZ#!O*>
nSplitter = nCount; ]{)a,c NG
} aGrIQq/k)%
} 1t:Q_j0Ym
WKts[Z
bZnuNYty75
/* p#01gB
**Utility.java K,Ef9c/+K
*/ ^!<U_;+
package NetFox; l7XUXbYp&=
!^^?dRd*v
;;_,~pI?k
public class Utility { eV2W{vuI
#+:9T/*>0
8;d:-Cp
public Utility() W3]_m8,Z
{ 8qk?E6
.GsV>H
6bomh2
} X@$f$=
j2Cks_$:
//线程睡眠 nG,A@/N
public static void sleep(int nSecond) 49rf7NT-g
{ )_+rU|We
try{ <>dT64R|
Thread.sleep(nSecond); .R)D3NZp
} |XT)QK1
catch(Exception e) D8inB+/-
{ KX76UW
e.printStackTrace (); HFKfkAl
} ) brVduB
} T_s_p
Y#!UPhg<
//日志 4E;VM{
public static void log(String sMsg) [="e ziM{
{ b=g8eMm
System.err.println(sMsg); GQt8p[!
} d:ARf
O-ew%@_
H2&@shOOQJ
public static void log(int sMsg) N^#ZJoR
{ M}`B{]lLz
System.err.println(sMsg); 98j>1"8
} ~T ]m>A!
} Z,RzN5eN
O,J>/
8J=?5
/* .Obw|V-
**TestMethod.java y[`l3;u:'
*/ _a5d?Q9Z
package NetFox; pf%=h |
!g?|9
`s"'r !
public class TestMethod { _4rFEYz$d
'[U8}z3
=q>'19^Jx
public TestMethod() >/:" D$
{ ///xx/weblogic60b2_win.exe JI?rL
try{ = 6tHsN23
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5\N(PL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); M3J#'%$
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?HTjmIb
fileFetch.start(); SHvq.lYJ
} Wl;.%.]>
catch(Exception e){e.printStackTrace ();} 0@yXi
b o0^3]Z
c]$i\i#
} qHsUP;7
,`wXg
pM^9c7@!:
public static void main(String[] args) Y&[1`:-~-
{ ~res V
new TestMethod(); :}yi-/_8!
} @AKn@T5
} JIOh#VNU
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