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)); zc,kHO|
} Td6Gu"
for(int i=0;i<nEndPos.length-1;i++) fD>0
{ _mi(:s(
nEndPos = nStartPos[i+1]; fxR}a,a
} $ 2/T]
nEndPos[nEndPos.length-1] = nFileLength; ,vN0Jpf}\8
} \q |n0>
} c2$&pZ M
A&dNCB
MZ/PXY
//启动子线程 `U~Y{f_!H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $AI0&#NM
for(int i=0;i<nStartPos.length;i++) bM%c*_$F7
{ lMcSe8LBQa
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vW\|% @hW,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [u=DAk?8
nStartPos,nEndPos,i); K9BoIHo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rwRb _eIj
fileSplitterFetch.start(); 5[1#d\QR
} K% Gbl#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y 8./)W&/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TNvE26.(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1|PmZPKq9n
nEndPos = " + nFileLength); #h#Bcv0 Z
// fileSplitterFetch[nPos.length-1].start(); |>Xw"]b;
TYs#v/)I
YflotlT}
//等待子线程结束 1V@\L|Y
//int count = 0; E\%'/3o
//是否结束while循环 INHN=KY{
boolean breakWhile = false; 0lvX,78G;
VB?mr13}G
H=7zd|W
while(!bStop) o`@B*, @
{ ~6hG"t]:
write_nPos(); I8<s4q
Utility.sleep(500); ElEa*70~g
breakWhile = true; <_|H]^o
bnWKfz5
/@*J\0h(-
for(int i=0;i<nStartPos.length;i++) O>![IH(L
{ rCmxv7" a}
if(!fileSplitterFetch.bDownOver) 8J-;/
{ tv_Cn w
breakWhile = false; Q9~UL^bF
break; i>M*ubWE4@
} :EUV#5V.
} 7 -(LWH
if(breakWhile) }UzO_&Z#6
break; <IF\;,.c
jZ'y_
MI!JZI$z5
//count++; FZ)Y<r8|s
//if(count>4) J{Z-4y
// siteStop(); \I\'c.$I.Y
} @QAyXwp
6$'6x2,
Wu 71q=
System.err.println("文件下载结束！"); OGy/8B2c
} GM/3*S$c
catch(Exception e){e.printStackTrace ();} N".-]bB
} LRhq%7p7
]Mh7;&<6[
d E@R7yU@
//获得文件长度 `;^%t
public long getFileSize() @UO=)PxN3
{ h&!k!Su3#
int nFileLength = -1; "~h.u
try{ V.IgEE]
URL url = new URL(siteInfoBean.getSSiteURL()); ,x+_/kqx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h>Z$ n`T
httpConnection.setRequestProperty("User-Agent","NetFox"); oE&Zf/
y\ nR0m
ZSuMQ32
int responseCode=httpConnection.getResponseCode(); 3q:-98DT
if(responseCode>=400) NVnKgGlHgd
{ /HNZwbh]uJ
processErrorCode(responseCode); 7p?6j)rj
return -2; //-2 represent access is error Y/t:9Aau
} k3m|I*_\L
p6V`b'*>
+ R)x5
String sHeader; Q#@gOn=W\
5L<}u`0J
?=<vC
for(int i=1;;i++) `>fN?He
{ JlsRP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?lxI& h
//Utility.log(in.readLine()); eiZv|?^0
sHeader=httpConnection.getHeaderFieldKey(i); auP:r
if(sHeader!=null) EX>|+zYL
{ ~'WvIA (
if(sHeader.equals("Content-Length")) ufdC'2cp8
{ Z6&s 6MF
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =+{.I,g}g@
break; `8F%bc54iw
} ZkYc9!anY
} DPnKr/
else {uO8VL5+Qx
break; x8T5aS
} ]{OEU]I@
} Tk-PCra
catch(IOException e){e.printStackTrace ();} ?lb1K'(
catch(Exception e){e.printStackTrace ();} do{#y*B/g!
nzDS
G'( %8\
Utility.log(nFileLength); 6|#^4D)
pBt/vSad
\n850PS
return nFileLength; $JTy`g0>x
} n@BE*I<"
oKTIoTb
_QtqQ~f
//保存下载信息（文件指针位置） uNnwz%w
private void write_nPos() ewgcpV|spn
{ @2 dp5
try{ rsfA.o
output = new DataOutputStream(new FileOutputStream(tmpFile)); ',0~\V
output.writeInt(nStartPos.length); vjJ!d#8
for(int i=0;i<nStartPos.length;i++) Cc]s94
{ #;H,`r
// output.writeLong(nPos); QB@qzgEJ!,
output.writeLong(fileSplitterFetch.nStartPos); N_L&!%s
output.writeLong(fileSplitterFetch.nEndPos); Bh*~I_Ta>
} wCBL1[~C
output.close(); UTUIL D
} @( 9#\%=
catch(IOException e){e.printStackTrace ();} #hd<5+$U}l
catch(Exception e){e.printStackTrace ();} Wuosr3P
} .c"UlOZ&w^
"yc/8{U
MPO!qSS]
//读取保存的下载信息（文件指针位置） C[rYVa .
private void read_nPos() Y[T;j p(k
{ <_ */
try{ aQN`C{nY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #rV=!j||
int nCount = input.readInt(); /[[zAq{OA
nStartPos = new long[nCount]; N)RWC7th{
nEndPos = new long[nCount]; 9Pd~
for(int i=0;i<nStartPos.length;i++) %@Ks<"9
{ PZpwi?N
nStartPos = input.readLong(); ~>D;2 S(a
nEndPos = input.readLong(); OP2!lEs
} da!N0\.1T
input.close(); HtEjM|zj
} 8Mg4y1)RU
catch(IOException e){e.printStackTrace ();} ER5Q` H
catch(Exception e){e.printStackTrace ();} S M987Y!B
} qB]z"Hfq,
X>%2\S
2>fG}qYy$
private void processErrorCode(int nErrorCode) ]rn!+z
{ lIzJO$8cM
System.err.println("Error Code : " + nErrorCode); [p!C+|rro
} Eg-b5Z);
#Opfc8pm'
An[*Jx
//停止文件下载 u{H,i(mx?
public void siteStop() 7L;yN..0
{ e^&YQl
bStop = true; um#;S;
for(int i=0;i<nStartPos.length;i++) (fh:q2E#
fileSplitterFetch.splitterStop(); NFLmM
B[4y(Im
/GM-#q a
} Z mi<Z
} J~gfMp.
//负责部分文件的抓取 f`A
**FileSplitterFetch.java T,7Y7MzF
*/ tt J,rM
package NetFox; G:WMocyXI'
]N=C%#ki!
`yYgL@Zt
import java.io.*; q3NS?t!
import java.net.*; tx5_e[
308w0eP
a' #-%!]
public class FileSplitterFetch extends Thread { Q(]-\L'
;S?1E:\av
K/\#FJno
String sURL; //File URL $Q{1^
long nStartPos; //File Snippet Start Position 0M8JE9 Kx
long nEndPos; //File Snippet End Position aGpRdF1;!
int nThreadID; //Thread's ID zo} SS[
boolean bDownOver = false; //Downing is over 4#2iL+
boolean bStop = false; //Stop identical ~BS*x+M
FileAccessI fileAccessI = null; //File Access interface i6`8yw
_&(ij(H
87<y_P@{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'hya#rC&(
{ K7f-g]Ibdn
this.sURL = sURL; m qw!C
this.nStartPos = nStart; lmmyDg1R
this.nEndPos = nEnd; [7I|8
nThreadID = id; )&dhE^ O
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d}l^yln
} cC}s5`
VpVw:Rh>
huKz["]z[
public void run() p*npY"}v
{ YSa:"A
while(nStartPos < nEndPos && !bStop) hq,;H40%/
{ [tD*\\IA
e/Q[%y.X
5\4>H6
try{ o~4n8
URL url = new URL(sURL); !zJ.rYZ=g`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c(Ha"tBJ
httpConnection.setRequestProperty("User-Agent","NetFox"); rM=Hd/ki5
String sProperty = "bytes="+nStartPos+"-"; {eZj[*P
httpConnection.setRequestProperty("RANGE",sProperty); #[KwR\b{:+
Utility.log(sProperty); :X4\4B*~
M9&tys[KX
8dA/dMQ
InputStream input = httpConnection.getInputStream(); $s]@%6f
//logResponseHead(httpConnection); iMA)(ZS
%BG5[XQ7
Y}?@Pm drz
byte[] b = new byte[1024]; so8-e
int nRead; 23OVy^b
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) aSF&^/j
{ 6op\g].P
nStartPos += fileAccessI.write(b,0,nRead); RDqC$Gu
//if(nThreadID == 1) /GeS(xzQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZDDwh&h
} ,@!d%rL:4]
S~TJF}[k^6
Z^~6pH\
Utility.log("Thread " + nThreadID + " is over!"); 3\WES!
bDownOver = true; ?x[>g!r
//nPos = fileAccessI.write (b,0,nRead); kW:!$MX!
} C,<TAm
catch(Exception e){e.printStackTrace ();} _:K}DU'6
} jU#%@d6!#
} nb|MHtPX
`nM4kt7
-[`W m7en
//打印回应的头信息 0[i]PgIH
public void logResponseHead(HttpURLConnection con) ]Aluk|"`U
{ 5Y&@ :Y
for(int i=1;;i++) (qG$u&
{ 4[-9$ r
String header=con.getHeaderFieldKey(i); )Z_i[1V
if(header!=null) =|#-Rm^YB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); nx+& {hn(
Utility.log(header+" : "+con.getHeaderField(header)); W1!eY,1}
else "Jwz.,Y\
break; 2kgm)-z
} 0jzA\$oD
} ]e3nnS1*.
w[+!c-A:H
5;Z~+$1
public void splitterStop() ""a8eB6
{ co@8w!W
bStop = true; lz*2wGI9
} jFc{$#g-
x!jhWX
Lf:Z (Z>
} )~n}ieS
' FK"-)s
Wm,,OioK
/* fE:2MW!)*
**FileAccess.java [5 V
*//文件访问(定位，写) z7_./ksQ
package NetFox; jl@8pO$
import java.io.*; <>:kAT,sP
M@K[i*e
w}i.$Qt
public class FileAccessI implements Serializable{ i,HAXPi
,@;<u'1\G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [y:LA~q
RandomAccessFile oSavedFile; \'KzSkC8
long nPos; QezK&iJg
?l(hS\N,
Q4PXC$u
public FileAccessI() throws IOException Ygl!fC 4b
{ {HU48v"W
this("",0); Cnr48ukq
} TGLXvP& \
re!CF8 q
QHh#O+by#
public FileAccessI(String sName,long nPos) throws IOException AK!G#ug
{ S=2,jPX2r
oSavedFile = new RandomAccessFile(sName,"rw"); EGt)tI&
this.nPos = nPos; )?WoLEjq
oSavedFile.seek(nPos); U_~~PCi
} f,#xicSB*
E*l"uV
;:4puv+]
public synchronized int write(byte[] b,int nStart,int nLen) '$zFGq }}
{ hMQaT-v
int n = -1; 0>`69&;g|
try{ smU+:~
oSavedFile.write(b,nStart,nLen); z)B=<4r
n = nLen; }VGiT~2$
} Uww^Sq
catch(IOException e) _6' g]4
{ b+hY^$//
e.printStackTrace (); .<B1i
} hTm}j,H
[ n2udV
+=_Pl7?
return n; 7`}z7nk
} P33E\O
kYAvzuGRb
nGVqVSxKT
} 9PAp*`J@kr
p1nA7;B-m
2&m7pcls
/* L7-nPH
**SiteInfoBean.java nM`)`!/
*/ A M2M87{t
package NetFox; -,dQ&Qf?
D|o@(V
%8Z,t+'
public class SiteInfoBean { qHCs{ u
X3[!xMij
:dzU]pk%0
private String sSiteURL; //Site's URL +0 MKh
private String sFilePath; //Saved File's Path Sx2j~(pOr
private String sFileName; //Saved File's Name IoA;q)
private int nSplitter; //Count of Splited Downloading File BR2y1Hfi
J.nq[/Q=
q~n2VU4L*
public SiteInfoBean() )VT/kIq-U
{//nSplitter的缺省值为5 bnGA.b
//default value of nSplitter is 5 ho1F8TG=
this("","","",5); 3_$eQ`AAA
} Ub,unU
"}! rM6 h
{76!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) SOmn2 }
{ [/G;XHL;?
sSiteURL= sURL; R5"p7>
sFilePath = sPath; T8-$[ 2
sFileName = sName; :3f2^(b~^
this.nSplitter = nSpiltter; ^&iV%vQ[
u*{ _WL[(
.a*$WGb
} 1' m $_
9f\8oJQ
^v-'=1ub?
public String getSSiteURL() 919g5f`
{ QGd- 9UEA]
return sSiteURL; p0K;m%
} ~\ f^L?m
UsN b&aue
i1\2lh$
public void setSSiteURL(String value) BvF_9
{ #=(op?]
sSiteURL = value; Q\L5ZJ%y/
} fXe-U='
!Yu-a!
ItADO'M
public String getSFilePath() Gq/6{eRo\
{ k5D'RD
return sFilePath; ;L2bC3
} rzDJH:W{2
4&e@>
?LI9F7n
public void setSFilePath(String value) N_D+d4@
{ 2(Uz9!<V
sFilePath = value; 2-aYqMmT;
} sv"mba.J
M%xL K7
s2~dmZ_B|_
public String getSFileName() *GP_ut%
{ GDp p`'\
return sFileName; !T#y r)
} p^P y,
OPW"ABJ
,<b|@1\k
public void setSFileName(String value) _~Vz+nT
{ ~uadivli
sFileName = value; S7{.liHf
} % VpBB
nM-SDVFM
CqK#O'\
public int getNSplitter() {yMA7W7]
{ v`^J3A
return nSplitter; UUu-(H-J
} *`Xx_
}Y`<(V5:
bpa O`[*
public void setNSplitter(int nCount) ]31XX=
{ Xe;(y "pR
nSplitter = nCount; 8Ql'(5|T
} bs EpET
} W'h0Zg
S.|kg2
AYIz;BmWy
/* <[:7#Yo g
**Utility.java 6L9[U^`@
*/ d`uO7jlm
package NetFox; v9m;vWp
+\GZ(!~
lk1Gs{(qhH
public class Utility { @B[Cc`IN"
l/zC##1+.
P<!$A
public Utility() (%yc5+f!
{ !]+Z%ed`%
5!jNL~M
6F.7Ws<
} nDB 2>J
1]Q2qs
//线程睡眠 #0hNk%X=
public static void sleep(int nSecond) "%''k~UD4
{ &4&33D
try{ .#55u+d,
Thread.sleep(nSecond); 4z%#ZIy3
} rn:zKTyhw
catch(Exception e) 34wM%@D*c
{ gT&'i(c
e.printStackTrace (); in#]3QGV
} m+2`"1IE[
} 4bev*[k
$KWYe{#
//日志 }?]yxa~
public static void log(String sMsg) D?yE$_3>c
{ H9VXsFTW
System.err.println(sMsg); |\|)j>[i
} b>=Wq
>q@Sd
MiH}VfI
public static void log(int sMsg) 6w"( y~c1
{ !Nl.Vb
System.err.println(sMsg); M*|VLOo=v
} }"?nU4q;S
} Zxc7nLKF~
(s$u_aq77
? x"HX|n
/* !@<@QG-
**TestMethod.java [Z5[~gP3
*/ -9>LvLU
package NetFox; dG-or
XQ3*
4Kn9*V
public class TestMethod { mvq7G
PB(
mPfUJ#rS
public TestMethod() 1%spzkE 3P
{ ///xx/weblogic60b2_win.exe 6UW:l|}4#2
try{ 9Ue7 ~"=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uR:=V9O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~z K@pFeH
SiteFileFetch fileFetch = new SiteFileFetch(bean); ihiuSF<NaQ
fileFetch.start(); twtkH~`"Q
} O5qW*r'
catch(Exception e){e.printStackTrace ();} %x}&=zx0*1
Y62u%':X
wY3|#P CDV
} K6v $#{$6
aM{@1mBm
8pk#sJ51
public static void main(String[] args) f(6UL31
{ 8wX+ZL:9
new TestMethod(); UOWIiu
} :'y{dbKp"
} <r<Dmn|\a
点击下载更多相关资料