http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); nV?e(}D
} j*@EJ"Gm>
for(int i=0;i<nEndPos.length-1;i++) /Wm3qlv
{ 4(}V$#^+
nEndPos = nStartPos[i+1]; (khMjFOg
} {#uf#J|
nEndPos[nEndPos.length-1] = nFileLength; kI#yW!
} y ;T=u(}
} di#:KW
NFlrr*=t>
%z AN@
//启动子线程 )\0LxsZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tU(vt0~b
for(int i=0;i<nStartPos.length;i++) "(SZ;y
{ |>AHc_:$$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3']=w@~ O[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Lw #vHNf6
nStartPos,nEndPos,i); aG/L'weR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aT%6d@g
fileSplitterFetch.start(); 4Nz]LK%@
} .eM A*C~n
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (%f2ZNen
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (= ,w$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +#0,2wR#
nEndPos = " + nFileLength); ttC+`0+H
// fileSplitterFetch[nPos.length-1].start(); ~:lN("9OI
}e0)=*;l
Zk75GC
//等待子线程结束 ,[0rh%%j
//int count = 0; eXZH#K7S#
//是否结束while循环 A;#GU`
boolean breakWhile = false; $sR-J'EE!
4|DGQ
MbeO(Q
while(!bStop) Xw[|$#QKM
{ XveG#oyiU
write_nPos(); 6?(vXPpT$
Utility.sleep(500); \Dn an5H/
breakWhile = true; MnymV;y"
Y'%k G5nF
G/5]0]SO
for(int i=0;i<nStartPos.length;i++) m;"dLUb
{ f1UGDC<p9
if(!fileSplitterFetch.bDownOver) &nEQ`3~F
{ by%k*y
breakWhile = false; Cz1o@rt
break; l:rT{l=8*
} a#:K"Mf.
} ^zVBS7`J
if(breakWhile) .|9o`mF7
break; !]z6?kUK
S`?cs^?
gw);b)&mx
//count++; _f5n t:-
//if(count>4) B\}B H
// siteStop(); 5(sWV:_2
} gzDNMM
pJ 7="n
>rb8A6
System.err.println("文件下载结束！"); 2pQdDbm
} C[h^bBq
catch(Exception e){e.printStackTrace ();} +HOHu*D
} -%#F5br%
"G3zl{?GP
8o4?mhqV
//获得文件长度 S;FgS:;
public long getFileSize() 8h| 9;%
{ O'} %Bjl
int nFileLength = -1; C7lBK<gQ
try{ %1oG<s
URL url = new URL(siteInfoBean.getSSiteURL()); $9Yk]~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h16i]V
httpConnection.setRequestProperty("User-Agent","NetFox"); $5n6C7
G`" 9/FI7
96$qH{]Ap
int responseCode=httpConnection.getResponseCode(); #+,O
if(responseCode>=400) m=uW:~
{ 9!06R-h
processErrorCode(responseCode); O A9G] 8k
return -2; //-2 represent access is error R8<'m
} b4HUgW3Ac
8hx 3pvmk
g`BtG
String sHeader; 1-M\K^F
+Y
{a `#O9
for(int i=1;;i++) P,@ :?6
{ ?nya;Z-~Hc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )KPQ8y!d
//Utility.log(in.readLine()); <(U:v
sHeader=httpConnection.getHeaderFieldKey(i); &7CAxU;i3
if(sHeader!=null) m|5yET
{ M(_1'2
if(sHeader.equals("Content-Length")) m"CsJ'\ors
{ 4pfv?!Oj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5@xl/
break; ;%H/^b.c
} K!MIA
} |tkhsQ-;
else *j0kb"#
break; LYv$U;*+
} hD5G\TR.
} mSu1/?PS
catch(IOException e){e.printStackTrace ();} rcWr0q
catch(Exception e){e.printStackTrace ();} Jm l4EW7
(\=iKE4#
OYsG#
Utility.log(nFileLength); v)a$;P%
2Xt$KF,?
;ESuj'*t
return nFileLength; C=z7Gk=
} X_0Ta_u?T
UmRI! WQl
k}yUD 0Y
//保存下载信息（文件指针位置） uS%Y$v
private void write_nPos() C {GSf`D!T
{ -`o22G3w
try{ 8=#J:LeXj
output = new DataOutputStream(new FileOutputStream(tmpFile)); w9J^s<e
output.writeInt(nStartPos.length); RI q9wD}4(
for(int i=0;i<nStartPos.length;i++) xxlYn9ke
{ "$VqOSo
// output.writeLong(nPos); @+3@Z?!SZ
output.writeLong(fileSplitterFetch.nStartPos); i"{ \ >
output.writeLong(fileSplitterFetch.nEndPos); x3JX}yCX
} X~ AE??
output.close(); '<35XjW
} 1~HR;cTv=
catch(IOException e){e.printStackTrace ();} }LaRa.3
catch(Exception e){e.printStackTrace ();} J,bE[52
} 9ntXLWK7e
3 oG5E"G
-R[ *S "
//读取保存的下载信息（文件指针位置） n' \poB?
private void read_nPos() g`}+K U
{ '01ifA^
try{ ,KMt9<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %S<0l@=5`l
int nCount = input.readInt(); _Co*"hl>2
nStartPos = new long[nCount]; +s}"&IV%
nEndPos = new long[nCount]; ,c%>M^d
for(int i=0;i<nStartPos.length;i++) 7n1@m_7O
{ )K4A-9pC
nStartPos = input.readLong(); j(`L)/|O
nEndPos = input.readLong(); h7( R/Rf
} p)$DpNL% p
input.close(); ZPT6 pJ
} Kug_0+gI
catch(IOException e){e.printStackTrace ();} Fnnk}I}
catch(Exception e){e.printStackTrace ();} wi]F\ q"Y^
} :CQ-?mT^LA
a/Cd;T2
.7ZV:m
private void processErrorCode(int nErrorCode) k|^e=I
{ m{/?6h 1
System.err.println("Error Code : " + nErrorCode); b|cUKsL5
} ng-g\&-
z]NzLz9VfL
V'";u?h#S
//停止文件下载 |g3a1El
public void siteStop() >&|C E2'
{ _7AR2
bStop = true; BnLM;5 >
for(int i=0;i<nStartPos.length;i++) ?(&)p~o
fileSplitterFetch.splitterStop(); VPB,8zb]
bN6FhKg|
cI9}YSk
} #)aUKFX
} iI27N'g
//负责部分文件的抓取 liW0v!jBo
**FileSplitterFetch.java qeK_w '
*/ V Q6&7@ c
package NetFox; <$^76=x,8P
z*cC2+R}=
XNwZSW
import java.io.*; .kl _F7
import java.net.*; ]*8K4n G
.Y8z3O
f_*Bd.@
public class FileSplitterFetch extends Thread { 1N#KVvK
8\+Q*7~@i
Jon<?DQj
String sURL; //File URL .e $W(}
long nStartPos; //File Snippet Start Position akuV9S
long nEndPos; //File Snippet End Position M(l>^N8W8
int nThreadID; //Thread's ID >Cb[
boolean bDownOver = false; //Downing is over Vf67gux
boolean bStop = false; //Stop identical 4,o|6H
FileAccessI fileAccessI = null; //File Access interface -.8 nEO3
mCa[?
YxEc(a"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException K5O#BBX=
{ zFy0SzF
this.sURL = sURL; wzr3y}fCe
this.nStartPos = nStart; u? a*bW
this.nEndPos = nEnd; p#VA-RSUQ|
nThreadID = id; N|n"JKw)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,4bqjkX5q
} "T`Q,
}1ABrbc
@S/jVXA
public void run() ;]* %wX
{ H\OV7=8
while(nStartPos < nEndPos && !bStop) SH"e x,=
{ Iv6(Z>pAB
^f:oKKaAW;
qSRE)C=)
try{ (x{6N^J.t
URL url = new URL(sURL); RR u1/nam
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1LbJR'}
httpConnection.setRequestProperty("User-Agent","NetFox"); T)"B35
String sProperty = "bytes="+nStartPos+"-"; n+db#qAj5
httpConnection.setRequestProperty("RANGE",sProperty); lKo07s6u
Utility.log(sProperty); z\zmAus
IXp(Aeb
qVOlUH
InputStream input = httpConnection.getInputStream(); _raj b1!
//logResponseHead(httpConnection); `K.2&6xc
0B0Uay'd_
lx8@;9fLy
byte[] b = new byte[1024]; B'( /W@
int nRead; O7p>"Bh
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p`@7hf|hm
{ |K(j}^1k
nStartPos += fileAccessI.write(b,0,nRead); ~_SoP
//if(nThreadID == 1) H"_ZqEg
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :zXkQQD8`
} v(+9&
1l$c*STK
;++CMTza]
Utility.log("Thread " + nThreadID + " is over!"); #&JhA2]q
bDownOver = true; j[zo~Y4z
//nPos = fileAccessI.write (b,0,nRead); #HjiE
} Ww9%6 #it
catch(Exception e){e.printStackTrace ();} &,pL3Qos
} KLpe!8tAe
} Xx~za{p
3snr-)
%?gh;? GD
//打印回应的头信息 *Uvh;d{
public void logResponseHead(HttpURLConnection con) Zi&qa+F
{ `Pa)H
for(int i=1;;i++) PNwXZ/N%
{ {H FF|Dx
String header=con.getHeaderFieldKey(i); (1`z16
if(header!=null) ['p%$4i$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); C5Fk>[fS
Utility.log(header+" : "+con.getHeaderField(header)); |D `r o
else 86bl'FdKS
break; L*TPLS[lh
} OR4ZjogzY
} zmV5k
L0\97AF
pBW|d\8
public void splitterStop() #/u%sX`#y
{ &/K:zWk3mx
bStop = true; 7X\azL
} !&f(Xs
vYT%e:8)q
Nqih LUv
} E'|@hL-jn
CAGaZ rx
.G"UM>.}d
/* @<$-*,
**FileAccess.java ig Mm.1>
*//文件访问(定位，写) W2CCLq1(
package NetFox; :JBvCyj4PE
import java.io.*; Qqt<
%nU8 Ca
5(@P1Bi
public class FileAccessI implements Serializable{ ( Z-~Eh
5r;M61
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ok7i^-85
RandomAccessFile oSavedFile; i *W9 4
long nPos; 8*sZ/N.
ich\`j[i
cR0+`&
public FileAccessI() throws IOException K OZHz`1!
{ {fi:]|<1h
this("",0); ES~ykE
} %i!&Fr
&&Sl0(6x[T
{VWX?Mm
public FileAccessI(String sName,long nPos) throws IOException #b[B$
{ EZ+_*_9
oSavedFile = new RandomAccessFile(sName,"rw"); GEr]zMYG[A
this.nPos = nPos; 'g<0MOq{
oSavedFile.seek(nPos); JGS4r+
} mlolSD;7
lM1Y }
^4Ta0kDn
public synchronized int write(byte[] b,int nStart,int nLen) D8u_Z<6IjI
{ V~rF`1+5N
int n = -1; \}O'?)(1
try{ ZJL[#}*
oSavedFile.write(b,nStart,nLen); .}QR~IR'
n = nLen; gAcXd<a0
} X@$x(Zc
catch(IOException e) %]/O0#E3Kz
{ &yFt@g]
e.printStackTrace (); ~(2G7x)
} &"vh=Z-
"Dbjp5_
wyqXD.of
return n; JFw<Po,MEa
} k_)H$*
^rd]qii"
1b)^5U ;
} :OC`X~}Rc
'%&i#Eb
q4)8]Y2
/* V#!ftu#c?
**SiteInfoBean.java \ "193CW!
*/ Vj^<V|=
package NetFox; AplXl=
vh8{*9+
Eeemy*U
public class SiteInfoBean { vAW+ ,Rfj
,(0q
cC'{+j8-a
private String sSiteURL; //Site's URL Og8:
private String sFilePath; //Saved File's Path h#K863
private String sFileName; //Saved File's Name :'-FaGy
private int nSplitter; //Count of Splited Downloading File vas
Xj:?V;
]d]tQPEU
public SiteInfoBean() D'y/pv}!
{//nSplitter的缺省值为5 s'yA^ VPf
//default value of nSplitter is 5 $xT'cl/IH
this("","","",5); !"\UT&
} LD]>_P83
4u;db_gX
cX$ Pq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) # [c`]v
{ ;IX3w:Aw
sSiteURL= sURL; SWujj,-[
sFilePath = sPath; q.L0rY!
sFileName = sName; #S+GI!
this.nSplitter = nSpiltter; cES3<`[K
3cK`RM `
8NLTq|sW
} }a= &o6=
/`yb75
=k]RzeI
public String getSSiteURL() <5*cc8
{ $Bd{Y"P@6
return sSiteURL; 9)={p9FZY
} I>X_j)
\D8d!gr
K9Dxb
public void setSSiteURL(String value) {3Z&C$:s
{ R3;GMe@D#
sSiteURL = value; Fxwe,
} '\ec ,&4Z
"y@B|
|sWH!:]49
public String getSFilePath() "7_6iB&@<
{ yE3g0@*
return sFilePath; mO$]f4}
} &E.ckWf
z@hlN3dg
Yrp WGK520
public void setSFilePath(String value) qv<[f=X9|
{ 6AgevyVG
sFilePath = value; BwO^F^Pr?k
} f`@$saFD
^` N+mlh
BR5r K
public String getSFileName() )cc:Z7p
{ :4|W;Lkd!
return sFileName; gD0O7KO
} d)m+Hc.
.{as"h-.O
4}B9y3W:v
public void setSFileName(String value) 7_>No*[
{ (JS1}T
sFileName = value; X)iQ){21V
} mx s=<
|eIEqq.Eb
9W$FX
public int getNSplitter() \`?l6'!
{ a5o&6_
return nSplitter; 0ts] iQ7
} R[>fT}Lo
`mV&[`NZ
i,>yIPBU!
public void setNSplitter(int nCount) (C/2shr 8
{ ON~jt[
nSplitter = nCount; 9J% ~?k
} @]u nqCO
} c%Y%c2([
M{$EJS\d=
qX[a\HQa
/* >x0"gh
**Utility.java 1au1DvH
*/ "\bbe@
package NetFox; I, 9!["^|
@O b$w1c
_W]qV2j
public class Utility { L 1=HD
E/9h"zowS
,a&N1G.
public Utility() zg,?aAm
{ Rk8>Ak(/
a[iuE`
ur^)bp<n
} SBo>\<@
-d?9Acd
//线程睡眠 3uO#/EbS
public static void sleep(int nSecond) `MFw2nu@t
{ :JW!$?s8H
try{ xj~/C5@
Thread.sleep(nSecond); GEU:xn
} .-t#wXEi
catch(Exception e) \"BoTi'2!
{ Vrl)[st!;I
e.printStackTrace (); ;pu68N(B
} rnWU[U8%
} :X-Z|Pv8
mB&nN+MV
//日志 $@kGbf~k
public static void log(String sMsg) +9db1:
{ FWqnlK#
System.err.println(sMsg); 7g1"s1~or
} M^I*;{w6i
J+IQvOn_|
46c7f*1l
public static void log(int sMsg) ,@"Z!?e
{ =qH9<,p`H
System.err.println(sMsg); |5|^[v
} L|4kv
} !HyPe"`oL
6@kKr
y\L$8BSL
/* Nx>WOb98
**TestMethod.java >&V?1!N"
*/ 5`CPaJT$
package NetFox; yNVuSj
:|/bEP]p/
Rh#0EbE2
public class TestMethod { AA&398F
wWs<{ T
Zp~2WJQ
public TestMethod() Erz{{kf]1V
{ ///xx/weblogic60b2_win.exe {B$cd?}
try{ gAt[kW< n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /MHqt=jP6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); csZIBi
SiteFileFetch fileFetch = new SiteFileFetch(bean); Qzy[
fileFetch.start(); {H OvJ`tM
} yyZ}qnbx]
catch(Exception e){e.printStackTrace ();} Bs2.$~
oK1"8k|Z
yGl (QLk
} b5u_x_us|
\q#s/&b
z-(@j;.
public static void main(String[] args) GFd~..$
{ -AwR$<q'
new TestMethod(); @@$=MSN
} |0nbO2}
} .])ubK_9
点击下载更多相关资料