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)); @RG3*3(
} 9~ .BH;ku
for(int i=0;i<nEndPos.length-1;i++) Ra,on&OP`*
{ O8}s*}]
nEndPos = nStartPos[i+1]; U";Rp&\3;
} Z-r0 D
nEndPos[nEndPos.length-1] = nFileLength; gZuR4Ti
} N pIlQaMo4
} Fu=VY{U4
i3\oy`GJ
G}OrpPP
//启动子线程 6/[h24d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mgl' d
for(int i=0;i<nStartPos.length;i++) 'k) P(H
{ 6Yi,%#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZkG##Jp\>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4w
nStartPos,nEndPos,i); SodW5v a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Wh&Z *J
fileSplitterFetch.start(); cN(QTbyl6Q
} )9P
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TOP'Bmb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m*WEge*$t
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", p{_O*bo
nEndPos = " + nFileLength); &5CeRx7%
// fileSplitterFetch[nPos.length-1].start(); ]$X=~>w
. *+7xL
pc(9(. |
//等待子线程结束 FP cvkXQD
//int count = 0; hYQ%|CBXBR
//是否结束while循环 ).6/ii9gt
boolean breakWhile = false; l@2`f#y1~<
lJpv
7VD7di=D
while(!bStop) WxI]Fcb<
{ IQ`aDo-V
write_nPos(); m<;" 1<k
Utility.sleep(500); o`]FH_
breakWhile = true; +Gs;3jC^
m^&mCo,
*^m.V=
for(int i=0;i<nStartPos.length;i++) Gf$>!zXr
{ ojI"<Q~g
if(!fileSplitterFetch.bDownOver) Y{B_OoTun
{ 8TM=AV
breakWhile = false; K*D]\/;^
break; Y2~{qY
} 'r3}=z4Y
} H$'kWU*l
if(breakWhile) Y\2>y"8>$x
break; =<tEc+!T3
`o-<,
>~r@*gml
//count++; !,WRXE&j
//if(count>4) n_gB#L$
// siteStop(); gI$`d?[0{
} z?g4^0e
^E,UcK;
"s^@PzQpN
System.err.println("文件下载结束！"); ;^SgV
} 3W00,f^9
catch(Exception e){e.printStackTrace ();} KV(W|~+rM
} LA3,e (e
T"lqPbK
MO+0]uh:
//获得文件长度 Ft>8 YYyU
public long getFileSize() l"g%vS,;`
{ ;qQzF
int nFileLength = -1; D-EM
try{ f)fw87UPc
URL url = new URL(siteInfoBean.getSSiteURL()); alD|-{Bf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >}tG^)os
httpConnection.setRequestProperty("User-Agent","NetFox"); m$j;FKz+|
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UeTp,
int responseCode=httpConnection.getResponseCode(); rx)Q]
if(responseCode>=400) -B! TA0=oJ
{ k18V4ATE]
processErrorCode(responseCode); vK/Z9wR*05
return -2; //-2 represent access is error WWzns[$f
} oMf h|B
l$@lk?dc
1a4$. {
String sHeader; !0_Y@>2
q&x#S_!
"lAS <dq
for(int i=1;;i++) FV,SA3
{ mjc:0hH
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 09i[2n;O
//Utility.log(in.readLine()); 7guxkN#
sHeader=httpConnection.getHeaderFieldKey(i); Unk+@$E&
if(sHeader!=null) &?pAt30K:
{ %^A++Z$`
if(sHeader.equals("Content-Length")) qa#F}aGd
{ ^DJU99
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T!$HVHh&,}
break; 2?&ptN)`N
} `84yGXLK
} x$4'a~E
else XAkl,Y
break; 3mpjSL
} _3JTHf<+
} CKx}.<_
catch(IOException e){e.printStackTrace ();} 6d6SP)|j
catch(Exception e){e.printStackTrace ();} zh#uwT1u
)]Rr:i9n
I<f M8t.Y>
Utility.log(nFileLength); &KwtvUN{
XS@6jbLE
Q4 S8NqE
return nFileLength; +[qy HTcG
} #{PNdINoU
SJe;T
Nzt1JHRS
//保存下载信息（文件指针位置） SesO$=y
private void write_nPos() J>&GP#7}
{ w Nnb@
try{ s)=7tHoqB)
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^4i3#}
output.writeInt(nStartPos.length); WR%iUO40
for(int i=0;i<nStartPos.length;i++) OC.@C}u
{ M1\/ueOe
// output.writeLong(nPos); cQb%bmBc5
output.writeLong(fileSplitterFetch.nStartPos); h<q``hn>
output.writeLong(fileSplitterFetch.nEndPos); T!r7RS
} T9yW# .
output.close(); F*u;'K
} c7 -j
catch(IOException e){e.printStackTrace ();} |&.)_+w
catch(Exception e){e.printStackTrace ();} 4T-AWk
} oyY,uB.|
cgAcAcmY
}P#gXG
//读取保存的下载信息（文件指针位置） GW#Wy=(_
private void read_nPos() L x&ZWF$
{ XFYl[?`G
try{ X8TZePh
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [)?3Dp|MH
int nCount = input.readInt(); G@2M&0'
nStartPos = new long[nCount]; 1:8: yFV
nEndPos = new long[nCount]; 9IMcp~zX
for(int i=0;i<nStartPos.length;i++) e)8iPu ..
{ bv0 %{u&
nStartPos = input.readLong(); I Cs1=
nEndPos = input.readLong(); vhW'2<(
} ?*0kQo'
input.close(); 7y3; F7V
} *!kg@ _0K
catch(IOException e){e.printStackTrace ();} =T`-h"E~@
catch(Exception e){e.printStackTrace ();} *bK@A2`
} ,#6\:i
/zM7G?y
<R$|J|
private void processErrorCode(int nErrorCode) >F v8 -
{ AseY.0
System.err.println("Error Code : " + nErrorCode); !ywc).]e
} #SmWF|/
|SmN.*&(9
U;/ )V
//停止文件下载 @AFLFX]
public void siteStop() J^T66}r[f,
{ *W l{2&
bStop = true; Pa*yo:U'h
for(int i=0;i<nStartPos.length;i++) `y(3:##p
fileSplitterFetch.splitterStop(); n1|%xQBU@
kW9STN
bYfcn]N
} B(5g&+{Lq~
} h2nyP
//负责部分文件的抓取 |qD<h
**FileSplitterFetch.java s.U p<Rw
*/ o/xE O=AW
package NetFox; [F$3mzx
9UZX+@[F
()Z$j,2
import java.io.*; ]cD!~nJ
import java.net.*; l)Hu.1~
]z,?{S
nHX@
public class FileSplitterFetch extends Thread { ,~!lNyL
(~#9KA1A}
FVHL;J]nf1
String sURL; //File URL )Z#7%,o
long nStartPos; //File Snippet Start Position ,3K?=e2
long nEndPos; //File Snippet End Position AWzpk}\
int nThreadID; //Thread's ID :c>,=FUT
boolean bDownOver = false; //Downing is over F&Gb[Q&a8
boolean bStop = false; //Stop identical /"U<0jot
FileAccessI fileAccessI = null; //File Access interface q)/4i9
Tr8+E;;
F=#Wfl-o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bF.Aj8ZQ
{ qr*/}F6
this.sURL = sURL; '#fj)
this.nStartPos = nStart; AG?oA328
this.nEndPos = nEnd; 31}6dg8?n
nThreadID = id; _Cxs"to
fileAccessI = new FileAccessI(sName,nStartPos);//定位 anbr3L[!
} ZO,]h9?4
0bor/FU-d
-(jcsqDk
public void run() $_y"P
{ #S"=)BZ8L
while(nStartPos < nEndPos && !bStop) a?;{0I:Ln
{ PrCq JY
pd|s7
9Ah4N2nL-b
try{ q#Bdq8
URL url = new URL(sURL); nm)F tX|A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CAXU #
httpConnection.setRequestProperty("User-Agent","NetFox"); ("{'],>
String sProperty = "bytes="+nStartPos+"-"; *(rq AB0~
httpConnection.setRequestProperty("RANGE",sProperty); SF6n06UZu
Utility.log(sProperty); @!S5FOXipZ
|qBo*OcO
~9{.!7KPc
InputStream input = httpConnection.getInputStream(); Vrnx#j-U
//logResponseHead(httpConnection); (efH>oY[
TCVJ[LbJ
4x:fOhtP
byte[] b = new byte[1024]; ?h{&
int nRead; ;RR)C@n1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8WAg{lVs
{ M*x_1h5n
nStartPos += fileAccessI.write(b,0,nRead); 'F@'4[uda
//if(nThreadID == 1) A9"ho}<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }} IvZG&
} Nz m 7E]
mGIS[_dcs
G B15
Utility.log("Thread " + nThreadID + " is over!"); $+tkBM
bDownOver = true; TY?Fs-
//nPos = fileAccessI.write (b,0,nRead); aJub("
} xHf l>C'
catch(Exception e){e.printStackTrace ();} noacnQ_I$
} YcIk{_N3
} /t816,i
t({:TQ
nF)|oA
//打印回应的头信息 \=.iM?T
public void logResponseHead(HttpURLConnection con) "2 Kh2[K
{ @Fo0uy\G
for(int i=1;;i++) -G{}8GM
{ #{0c01JZ
String header=con.getHeaderFieldKey(i); RJ0w3T]7
if(header!=null) wqw$6"~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lOVsp#
Utility.log(header+" : "+con.getHeaderField(header)); (mv8_~F0
else Z yIn>]{
break; lO:[^l?F
} /Qbt
} n84*[d}t
#SO9e.yhI
y0Ag px
public void splitterStop() K(hqDif*6
{ R#oXQaBJ
bStop = true; 8NpQ"0X
} :=-h'<D
}v`5
BwbvZfV|
} n]|[|Rf1
q K]Wk+
NJ3b Oq
/* (}'0K?
**FileAccess.java {4 *ob@w*
*//文件访问(定位，写) B&"fPi
package NetFox; 6%:N^B=%}
import java.io.*; =YI<L8@g~
_Nw-|N.
euQd
public class FileAccessI implements Serializable{ ] OR]
A07FjT5w8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U)N;=gr\
RandomAccessFile oSavedFile; rNdap*.
long nPos; B+,Z 3*
41$7P[M;
[9X1;bO#f
public FileAccessI() throws IOException mim]nRd2v
{ dY|(
this("",0); gwNv;g
} ZfS-W&6Z
iGM-#{5
YYN=`ST
public FileAccessI(String sName,long nPos) throws IOException uYF_sf
{ 7n5bI\
oSavedFile = new RandomAccessFile(sName,"rw"); Drc\$<9c@
this.nPos = nPos; iYR8sg[' #
oSavedFile.seek(nPos); PbCXcs
} T~_+\w
^[!LU
!DXKn\aQf
public synchronized int write(byte[] b,int nStart,int nLen) D}Z].c@E
{ 4?;1cXXA
int n = -1; BoXQBcG]w
try{ ur"ckuG!9
oSavedFile.write(b,nStart,nLen); d.sxB}_O
n = nLen; hK?uGt d?
} `G,\=c~{A
catch(IOException e) y~jTI[kS
{ L=?Yc*vg
e.printStackTrace (); }m(u oT~
} &*r YY\I
&?v^xAr?B
+!CG'qyN>
return n; c[f
} ^|(F|Z
}"E?#&^
!Hxx6/
} }hhDJ_I5M
:voQ#f=
Sm{idky)[
/* ["kk.*&
**SiteInfoBean.java uveTx
*/ *q\Ve)E}
package NetFox; 5fjmr
fMy7pXa_
9ssTG4Sa
public class SiteInfoBean { Quqts(Q)+
C5$1K'X@
\GEFhM4)
private String sSiteURL; //Site's URL "o+< \B~
private String sFilePath; //Saved File's Path LY-fp+
private String sFileName; //Saved File's Name ?l &S:` L
private int nSplitter; //Count of Splited Downloading File p$0G EYwM
IR(qjm\V
mY+Jju1
public SiteInfoBean() km|;T!
{//nSplitter的缺省值为5 q{nNWvL
//default value of nSplitter is 5 /q0[T{Wz$
this("","","",5); jA?A)YNQb
} P|Dw+lQj
lQ {k
BRLrD/8Le
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qH1[BsOx
{ 4$oNh)+/h
sSiteURL= sURL; 40w,:$
sFilePath = sPath; .Ks%ar
sFileName = sName; L'iENZI$
this.nSplitter = nSpiltter; tURjIt,I
@G@,)`p4?
)v !GiZ"7
} J^m#984
E_[|ZrIO&*
e$u=>=jV]
public String getSSiteURL() rVB,[4N
{ W2?6f:
return sSiteURL; jdqVS@SD
} JR] /\(
l 8qCg/ew
O~?H\2S
public void setSSiteURL(String value) .76T<j_
{ QpxRYv
sSiteURL = value; % put=I
} |`B*\\1
hd0d gc
4jbqV
public String getSFilePath() <=[,_P6|
{ FrT.<3
return sFilePath; {]BPSj{B
} ek\8u`GC
+i HZ*
6[b'60CuZL
public void setSFilePath(String value) TwJiYXHw?
{ -FftEeo7
sFilePath = value; )WuU?Tn&
} ,<Zu4bww
,j E'd'$
Fjch<gAofS
public String getSFileName() T;!: A
{ }-4@EC>
return sFileName; zW.I7Z0^
} Jmg<mjq/G
Gmi ^2?Z(
R!{^qHb
public void setSFileName(String value) jeLRS8];
{ B?n 6o|8
sFileName = value; {| ~
} Kcf1$`F24
utOATjB.z
@{/GdB,}
public int getNSplitter() `s1>7XWf
{ r{2V`h1/|
return nSplitter; cBcfGNTJ~
} 9n9Z
l ld,&N8
ggn C #$
public void setNSplitter(int nCount) >1uo5,wrF
{ 9bu}@#4*
nSplitter = nCount; XK#~w:/fB
} h.T]J9;9
} B}S!l>.z
zNG]v?JAh
]6s7?07m4
/* 8.JFQ/)i
**Utility.java 76 nrDE
*/ +\Uq=@
package NetFox; [u*-~(
0ndk=V
,jH<i.2R
public class Utility { 3T1t !q4/5
m{#?fR=9
0SS,fs<w3
public Utility() J n>3c
{ Lsu_f'p0
>%6a$r~@
]cQYSN7!SY
} fGdT2}gd
80m<OW1
//线程睡眠 ;[nomxu|?
public static void sleep(int nSecond) D@W[Nd5MJ
{ k65V5lb
try{ _"0,
Thread.sleep(nSecond); 7+]+S`p
} ~t=73fwB
catch(Exception e) iEx sGn]2
{ ]F'o
e.printStackTrace (); vC#_PI
} |NMf'$
} 3g79pw2w=
)\aCeY8o
//日志 h95a61a,Vy
public static void log(String sMsg) -ElK=q
{ bv:M zYS
System.err.println(sMsg); OkNBP0e}
} 78~;j1^6u
J^w!?nk
<ztcCRov
public static void log(int sMsg) \|@u)n_
{ <Pn]{N
System.err.println(sMsg); LC>bZ!(i#
} e};\"^HH
} 'v^Zterr
dgEH]9j&
2K:Rrn/cR
/* 6[x6:{^J
**TestMethod.java ]&b>P ;j:
*/ h/goV
package NetFox; {)`tN&\
XfZ^,'z
OUtXu7E$
public class TestMethod { @LyCP4
BT*z^ZH
WY& [%r
public TestMethod() &"gQrBa
{ ///xx/weblogic60b2_win.exe #r,LV}*qg
try{ |YnT;q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C<B+!16
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); PKjM1wqaG@
SiteFileFetch fileFetch = new SiteFileFetch(bean); H@uDP
fileFetch.start(); ?y/LMja
} L#|6Lnp^
catch(Exception e){e.printStackTrace ();} ^{}$o#iof
vk><S|[n
Mn<#rBE B
} e+~Q58oD
a(#aEbN?d
FW@(MIH
public static void main(String[] args) zn)Kl%N^
{ "?HDv WP=w
new TestMethod(); "3;b,<0
} 'eYM;\%('
} )`z{T
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