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)); %H=^U8WB
} M8f[ck
for(int i=0;i<nEndPos.length-1;i++) TZa LB}4
{ t7,**$ST
nEndPos = nStartPos[i+1]; k~=P0";
} _ IlRZ}f
nEndPos[nEndPos.length-1] = nFileLength; H.)J?3
} G PL^!_
} ^6PKSEba
->J5|c#
*!`bC@E
//启动子线程 FQ]5W |e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @4P_Yfn
for(int i=0;i<nStartPos.length;i++) (FSa>
{ !1`f84d
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P&AaD!Qn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ])vqXjN6"
nStartPos,nEndPos,i); )T'~F
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @g1T??h
fileSplitterFetch.start(); )wk9(|[o
} =+"-8tz8FV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,sltB3f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %m "9 =C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r9~IR
nEndPos = " + nFileLength); t[\6/`YH
// fileSplitterFetch[nPos.length-1].start(); rz5@E
PH=O>a`a_O
JgcMk]|'
//等待子线程结束 c)SQ@B@q
//int count = 0; z"V`8D
//是否结束while循环 d@ tD0s
boolean breakWhile = false; 68nPz".X
UX)QdT45Mh
uo7[T*<Q
while(!bStop) "2`/mtMon
{ L+0O=zJF
write_nPos(); 3IQ-2 X--
Utility.sleep(500); 9oVprd>%@
breakWhile = true; j]6YLM@5$
gflO0$i
]O&yy{yYK
for(int i=0;i<nStartPos.length;i++) h BzZJ/jn
{ CjLiLB
if(!fileSplitterFetch.bDownOver) 6' 9zpe@`
{ {N@tJ,Fh{
breakWhile = false; D1cnf"y^
break; ~oeX0l>F
} 6tup^Rlo;$
} n/+G^:~_
if(breakWhile) LEY k
break; x^y&<tA
-Vj112 fI
aTE;Gy,W
//count++; O,0j+1?
//if(count>4) ]{=qdgJ
// siteStop(); 2jyxP6t
} &Pgk$e%>
R5fZ}C7
sb</-']a
System.err.println("文件下载结束！"); 3s_$.
} |7b@w;q,D
catch(Exception e){e.printStackTrace ();} !FeNx*31i
} y@dTdR2Wc
9+:<RFJ
b R9iqRbn
//获得文件长度 # 0/,teJk
public long getFileSize() 8%^W<.Y
{ -p f9Wk
int nFileLength = -1; u$+nl~p[&
try{ NzbHg p
URL url = new URL(siteInfoBean.getSSiteURL()); ?wMS[Kj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u{|^5%)
httpConnection.setRequestProperty("User-Agent","NetFox"); ?# )\SQ
Ikgia:/-Z
i/F].Sag
int responseCode=httpConnection.getResponseCode(); &5R-bYGW
if(responseCode>=400) l1]'3]P(
{ n;~6'fxe
processErrorCode(responseCode); ~{[,0,lWU
return -2; //-2 represent access is error Z+Ppd=||,
} qz|xow/ns@
qj,^"rp1:
sKDL=c;?j
String sHeader; It5n;,n
zc!q a"4yM
}1Pv6L(o)
for(int i=1;;i++) jW]Fx:mQi
{ iayxN5,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }K9Ji]tOK:
//Utility.log(in.readLine()); ybpU?n
sHeader=httpConnection.getHeaderFieldKey(i); q ?m<9`
if(sHeader!=null) GD#W=O
{ `qa>6`\
if(sHeader.equals("Content-Length")) / 2h6
{ L$=a,$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l#|M.V6G
break; &F|Wk,y
} S?#'Y*h
} tMr$N[@r
else gBo~NLrf
break; ^Rmrre`uU
} N1X;&qZDd
} IdciGS6t
catch(IOException e){e.printStackTrace ();} eLk:">kj
catch(Exception e){e.printStackTrace ();} }~! D]/B
D?r% Y
$TavvO%#
Utility.log(nFileLength); \D}$foHg
4 zipgw
A|BN>?.t
return nFileLength; s7:w>,v/
} ]VK9d;0D
o^<W3Z
fG|+!
//保存下载信息（文件指针位置） 10$:^
private void write_nPos() @wa<nYd
{ I7jIA>ZZi
try{ 'jBtBFzP-
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1:Xg&4s
output.writeInt(nStartPos.length); !4mAZF b
for(int i=0;i<nStartPos.length;i++) bE2{^5iG
{ A9M/n^61
// output.writeLong(nPos); GlaZZ,
output.writeLong(fileSplitterFetch.nStartPos); #oEq)Vq>g|
output.writeLong(fileSplitterFetch.nEndPos); bk4G+wGw
} ~)]n67Or~
output.close(); @v n%
} _Uup*#m
catch(IOException e){e.printStackTrace ();} >I9|N}I
catch(Exception e){e.printStackTrace ();} 2Q[q)u
} `}*jjnr"
)-S;j)(+
No(S#,vJ;
//读取保存的下载信息（文件指针位置） 5 OF*PBZ
private void read_nPos() u&$1XZ!es
{ B \>W
try{ G>W:3y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q?-uJ1J
int nCount = input.readInt(); |~YhN'OJ
nStartPos = new long[nCount]; 30L/-+r1
nEndPos = new long[nCount]; Tg6nb7@P
for(int i=0;i<nStartPos.length;i++) zjwo"6c>
{ 8'Q1'yc
nStartPos = input.readLong(); -/J2;AkGH
nEndPos = input.readLong(); LQ4F/[1}
} rOXh?r
input.close(); bv'Z~@<c
} sys;Rz2
catch(IOException e){e.printStackTrace ();} mNr<=Z%b
catch(Exception e){e.printStackTrace ();} /n#t.XJY*
} K]dX5vJw'
ceNJXK
`/eh
private void processErrorCode(int nErrorCode) StM)lVeF
{ pqxBu
System.err.println("Error Code : " + nErrorCode); 3G-f+HN^E
} }t5pz[zl
}#9 |au`
&3'zG)
//停止文件下载 r;OE6}L>
public void siteStop() aKkY)
{ YX19QG%
bStop = true; \DRYqLT`
for(int i=0;i<nStartPos.length;i++) F` ]s
fileSplitterFetch.splitterStop(); ~aRcA|`
7\JA8mm
~n!7 ?4%U
} C~:!WRCz
} iVb#X#
//负责部分文件的抓取 )lB*] n`Z]
**FileSplitterFetch.java _JXb|FIp
*/ 9/LJtM
package NetFox; B<?fD
>?0f>I%\
D_Cd^;b
import java.io.*; /S)&dN`
import java.net.*; i@`T_&6l
zd#/zUPI
K9f7,/
public class FileSplitterFetch extends Thread { %TRH,-@3h
n"Q fW~U
?kM53zbT#
String sURL; //File URL `PvGfmYOl
long nStartPos; //File Snippet Start Position Wy,Tf*[
long nEndPos; //File Snippet End Position }8&L?B;90
int nThreadID; //Thread's ID t!}?nw%$
boolean bDownOver = false; //Downing is over >,%7bq=T!
boolean bStop = false; //Stop identical .%N*g[J
FileAccessI fileAccessI = null; //File Access interface ppo\cy;
oi}\;TG
`(?x@Y>.Ht
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .=-K7.X.)
{ @X*r5hjc
this.sURL = sURL; F6\r"63
this.nStartPos = nStart; 'aW<C>
this.nEndPos = nEnd; E>6:59+
nThreadID = id; 'Z(4Wuwb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 EL-1o02-
} IEJp!P,E
7U{g'<
[!E~pW%|n
public void run() D^W?~7e^r
{ I@9k+JB
while(nStartPos < nEndPos && !bStop) 6sp?'GO`~
{ _"#ucM=B:-
)x*pkE**c
Gm1vVHAxv
try{ )0NE_AZ?
URL url = new URL(sURL); /4n:!6rt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DV!) n 6
httpConnection.setRequestProperty("User-Agent","NetFox"); 7A[`%.!F6
String sProperty = "bytes="+nStartPos+"-"; &-1;3+#w
httpConnection.setRequestProperty("RANGE",sProperty); _jCjq
Utility.log(sProperty); +A,t9 3:k
L(!mm
^atBf![
InputStream input = httpConnection.getInputStream(); :X;AmLf`2u
//logResponseHead(httpConnection); /IN/SZx
^04|tda
RW. >;|m
byte[] b = new byte[1024]; p%6j2;D
int nRead; t'0dyQ%u
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `[5QouPV
{ sj?7}(s
nStartPos += fileAccessI.write(b,0,nRead); +#!! 'XP
//if(nThreadID == 1) 5=--+8[ bV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N2^B
} ;{Kx$Yt+
0jN?5j
&u/T,jy`
Utility.log("Thread " + nThreadID + " is over!"); zWh[U'6
bDownOver = true; ]o]*&[C
//nPos = fileAccessI.write (b,0,nRead); qSWnv`hL
} =a.avOZ
catch(Exception e){e.printStackTrace ();} ^J=l] l
} xPi/nWl`|
} `?ijKZ}y5
\kGi5G]
@n##.th
//打印回应的头信息 /hMD Me
public void logResponseHead(HttpURLConnection con) s) vHLf4T
{ 6M`N| %
for(int i=1;;i++) Q+\?gU]
{ 8Dq;QH}
String header=con.getHeaderFieldKey(i); 0FV?By
if(header!=null) LGm>x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); w&7-:."1i
Utility.log(header+" : "+con.getHeaderField(header)); H `V3oS~}
else (fjAsbT
break; ~e<v<92Xu
} a9GLFA8Vq
} Vnv9<=R
eiaLzI,O
{rG`Upp
public void splitterStop() [J|)DUjt
{ @{Q[M3l
bStop = true; u9*}@{,
} v@0lTl_
0/."R;
;_lEu" -
} x_oL~~@
t4H@ZvAH0
0}UJP
/* {<HL}m@kQ
**FileAccess.java ;$y(Tvd;
*//文件访问(定位，写) lFNf/j^Z
package NetFox; heliL/
import java.io.*; >k?/'R
/IS j0"/$
#Pulbk8
public class FileAccessI implements Serializable{ @]#0jiS
vRLkz4z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @JWoF^U
RandomAccessFile oSavedFile; aNpeePF)z
long nPos; [*j C
6N&S3<c4JO
$GyO+xF
public FileAccessI() throws IOException "bRg_]\q6
{ >Udb*76 D
this("",0); ~R]E=/m|
} {Tp0#fi
DGx9 \8^
kN4nRW9z
public FileAccessI(String sName,long nPos) throws IOException n7"e 79
{ 6ZBg/_m
oSavedFile = new RandomAccessFile(sName,"rw"); av(d0E}}b
this.nPos = nPos; D@yg)$;z
oSavedFile.seek(nPos); yWACIaj
} XB)e;R
gOI#$-L
*=1;HN3
public synchronized int write(byte[] b,int nStart,int nLen) &t+
{ |#x;}_>7
int n = -1; .[hQ#3)W
try{ %:n1S]Vr
oSavedFile.write(b,nStart,nLen); 6rEt!v #K[
n = nLen; {6v|d{V+e
} /vl]Oa&U
catch(IOException e) !<!sB)
{ )""i"/Mn
e.printStackTrace (); OYJy;u3"
} }ZEh^zdz8
q!k F
AF1";duA
return n; <R7*00
} `)F lb|da
w|x=^
z I`'n%n=
} (XJehdB0
j=)Cyg3_%
z0Vd(QL
/* ,9q=2V[GP
**SiteInfoBean.java h'<}N
*/ F_!6C-z
package NetFox; n37C"qJ/i
]<q{0.
$V~r*#$.
public class SiteInfoBean { GA{>=Q_~
$EbxV"b+
2#LcL
private String sSiteURL; //Site's URL J"8bRp=/|
private String sFilePath; //Saved File's Path e| (jv<~r
private String sFileName; //Saved File's Name yUQ;tTI
private int nSplitter; //Count of Splited Downloading File GBvB0kC)c
VuwBnQ.2k
j?1\E9&4-Q
public SiteInfoBean() {nT !|S)$
{//nSplitter的缺省值为5 $Trkow%F]
//default value of nSplitter is 5 =1lKcA[z
this("","","",5); g/so3F%v .
} D5)qmu
6g!#"=ls;
R:B-4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) t'4hWNR'
{ )_b#c+
sSiteURL= sURL; &-+qB >SK>
sFilePath = sPath; sMli!u
sFileName = sName; #$%9XD3
this.nSplitter = nSpiltter; .9> er
YL&$cT]1
it\{#rb=4
} a=k+:=%y
XZuJ<]}X,
a=gTGG"9
public String getSSiteURL() &Z5$ 5,[
{ 0G9@A8LU
return sSiteURL; Giz9jzF\
} *#Hi W)
]c+qD,wqt>
<"/Y`/
public void setSSiteURL(String value) E8=.TM]L
{ %p"x|e
sSiteURL = value; '/SMqmi
} SxC$EQgL
$I-$X?
YWM$%
public String getSFilePath() GC H= X
{ Mq42^m:qe
return sFilePath; d6<,R;)
} u.0Z)j}N
{gl-tRC3
@.T'
public void setSFilePath(String value) J$&!Y[0
{ ]1%H.pF
sFilePath = value; }f^r@3Cb3
} eGvHU ;@
9#/z[!
<!K2xb-d^
public String getSFileName() gPe*M =iF
{ SS O$.rp
return sFileName; k\Oy\z@
} 5wRDH1z@{
>9F,=63A
d#I'9O0&
public void setSFileName(String value) k$}XZ,Q
{ O?D*<rwD
sFileName = value; ,Zzh.z::D
} %fh ,e5(LT
=9y'6|>l
2#@S6zc
public int getNSplitter() )& %X AW{
{ [f.[C5f%"'
return nSplitter; (p68Qe%OuG
} Lh"Je-x<<
@= 6}w_
3w ?)H
public void setNSplitter(int nCount) c>!>D7:7
{ >t'/(y
nSplitter = nCount; KI-E=<zt
} [xk1}D
} @8|- C
W )q^@6[d
rYeFYPS
/* rcq(p(!
**Utility.java g$?B!!qT
*/ s41<e"
package NetFox; wX#=l?,K
8~EDmg[
/%$'N$@f
public class Utility { Cq u/(=
vC$[Zm
QZ"Lh
public Utility() j3P)cz-0/L
{ er,R}v
Sq UoXNw
'_g8fz 3
} W&}R7a@:<~
MT$OjH'Q`
//线程睡眠 ^]Lr_k
public static void sleep(int nSecond) 7}%3Aw6]S
{ ^g~Asz5]
try{ &y mfA{s
Thread.sleep(nSecond); t}qoIxy)
} Io5-[d
catch(Exception e) G|'DAj%
{ '+Gt+Gq+
e.printStackTrace (); Y@TZReb
} +0.$w
} bh6Mh<+
g/mVd;#o
//日志 Up*p*(d3
public static void log(String sMsg) hrNri$
{ (".`#909
System.err.println(sMsg); /+"BU-aQk
} ]b.@i&M
IpoZ6DB$
|Ag~k? QC
public static void log(int sMsg) 7sC$hm]
{ O=MO M
System.err.println(sMsg); ]3NH[&+
} "|]'\4UdzQ
} 2!-ZNd:(+
LP7t*}PK
C=h$8Q
/* 8PDt 7 \
**TestMethod.java 9&g//JlD
*/ p` B48TW
package NetFox; 'vhgR2/
?c+_}ja,
f/&Dy'OV7
public class TestMethod { uwyzxj
gZM\RJZ_
SM@l4GH
public TestMethod() {Rc/Ten
{ ///xx/weblogic60b2_win.exe &%>l9~F'~
try{ 37v!:xF!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gJ+MoAM"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p=coOWOQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); gvr"F
fileFetch.start(); +%7yJmMw
} WT;=K0W6&
catch(Exception e){e.printStackTrace ();} u!k\W{
S3MMyS8
G{knO?BK
} KY!
sI@m"A
ZQD_w#0j
public static void main(String[] args) s!9.o_k
{ 14]!LgH
new TestMethod(); w[uK3Av
} ]~U4;
} ]chcRc[!
点击下载更多相关资料