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)); ^xqh!
} .-WCB
for(int i=0;i<nEndPos.length-1;i++) 8V}c(2m
{ C{2UPG4x
nEndPos = nStartPos[i+1]; |9_e2OwH
} 8uI^ B
nEndPos[nEndPos.length-1] = nFileLength; VJ=!0v
} U{ahA
} }:jXl!:V
7kJ,;30)
?C $_?Qi
//启动子线程 uk\GAm@O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b%)a5H(
for(int i=0;i<nStartPos.length;i++) 7s.sbP~
{ gl!3pTC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VFYJXR{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), GbL,k?ey
nStartPos,nEndPos,i); _@^msyoq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jXW71$B
fileSplitterFetch.start(); SR43#!99Q
} wkIH<w|jb
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P}VD}lEyO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^ )+tn
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /5=A#G
nEndPos = " + nFileLength); ~V./*CQ\c
// fileSplitterFetch[nPos.length-1].start(); .5I1wRN49
L1D%vu`
lT(MywNsg
//等待子线程结束 Xt7uCs
//int count = 0; vkt)!hl `
//是否结束while循环 q g%<>B&"
boolean breakWhile = false; l[.pI];T
!MGQ+bD6
F`38sq
while(!bStop) }NYsKu_cM
{ #MBYa&Tw7
write_nPos(); Gm6^BYCk
Utility.sleep(500); FijzO
breakWhile = true; ] xH `
XDI@mQmzB
SgY>$gP9S
for(int i=0;i<nStartPos.length;i++) JgxOxZS`@
{ c^=,@#
if(!fileSplitterFetch.bDownOver) !D6@\
{ ^$T>3@rDB
breakWhile = false; 1= <Qnmw
break; ~Aq UT]l
} :_?>3c}L
} GJ((eAS)
if(breakWhile) +Uk/Zg w^
break; s+(8KYTs`
VTV-$Du[}
goxgJOiB
//count++; U|y+k`
//if(count>4) w>!KUT
// siteStop(); )D#*Q~
} )fC^h=Qp
{WC{T2:8
A46y?"]/30
System.err.println("文件下载结束！"); k|g~xmI;
} IPY@9+]
catch(Exception e){e.printStackTrace ();} R_Z H+@O
} #nu?b?X'
G,$jU9 f
4K4?Q+?
//获得文件长度 .IG(Y!cB
public long getFileSize() mk0rAN
{ e<IT2tv>u
int nFileLength = -1; -ff*,b$Q/
try{ #PFf`7b,z
URL url = new URL(siteInfoBean.getSSiteURL()); ,I)/ V>u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?p}m[9@
httpConnection.setRequestProperty("User-Agent","NetFox"); mT)iN`$Y@
OP>'<FK
fwOvlD&e
int responseCode=httpConnection.getResponseCode(); m"xw5aa>
if(responseCode>=400) Z$+0gm\Cnw
{ WAob"`8]
processErrorCode(responseCode); Ao=.=0os
return -2; //-2 represent access is error ^(a%B
} % +eZ U)N
JA1(yt
+=:CW'B5
String sHeader; A3h[VnuG,
3g} ]nj:N
}9@,EEhg
for(int i=1;;i++) }t]CDa_n
{ y=q\1~]Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )TV'eq
//Utility.log(in.readLine()); QDyL0l{C
sHeader=httpConnection.getHeaderFieldKey(i); <G#JPt6
if(sHeader!=null) eyUo67'7
{ nKV1F0-
if(sHeader.equals("Content-Length")) vu1F
{ U*,5t81
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); dx:],VB
break; 7]G3yt->
} X_"TG;*$
} ]3C7guWz
else IEO5QV:u:
break; e>MC 3D`5
} ` 8.d
} mO]>(^c
catch(IOException e){e.printStackTrace ();} ^TnBtIU-B
catch(Exception e){e.printStackTrace ();} p"Fj6T2
O~w&4F;{
&s\w: 9In
Utility.log(nFileLength); Lymy/9
Eiwo==M
#=+d;RdlW
return nFileLength; H}X3nl\]
} {bl^O
q]<cn2
gNN{WFHQX:
//保存下载信息（文件指针位置） \u2p]K>
private void write_nPos() aQw?r
{ <{7B ^'
try{ t&0pE(MO/
output = new DataOutputStream(new FileOutputStream(tmpFile)); FhS:.
output.writeInt(nStartPos.length); ?MyXii<a
for(int i=0;i<nStartPos.length;i++) e=TB/W_
{ vA:1z$m
// output.writeLong(nPos); X8p-VCkV
output.writeLong(fileSplitterFetch.nStartPos); De\&r~bTW9
output.writeLong(fileSplitterFetch.nEndPos); h_Q9c
} 0I& !a$:
output.close(); jj.iW@m
} !{"{(h)+@
catch(IOException e){e.printStackTrace ();} mq su8ti
catch(Exception e){e.printStackTrace ();} h0d;a
} t-i;
KR%DpQ&{'
X.bNU
//读取保存的下载信息（文件指针位置） fD]}&xc
private void read_nPos() WFULQQ*
{ GR Rv0M
try{ -T`rk~A9A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); DNC2]kS<
int nCount = input.readInt(); 8"Hy'JA$O
nStartPos = new long[nCount]; {Jwh .bJ
nEndPos = new long[nCount]; t|%wVj?_
for(int i=0;i<nStartPos.length;i++) f9F@G&&Ugg
{ +A3@{2
nStartPos = input.readLong(); CsJw;]dYI
nEndPos = input.readLong(); uI!rJc>TX
} PW~+=,
input.close(); V8 }yK$4b
} [n44;
catch(IOException e){e.printStackTrace ();} xP "7B9B
catch(Exception e){e.printStackTrace ();} -]\UFR
} v:nm#P%P
tc.R(F96
5ZSV)$t
private void processErrorCode(int nErrorCode) f3[gAY
{ d.3-@^P
System.err.println("Error Code : " + nErrorCode); X@2[!%nm
} :B6hYx
(Xi?Y/
YJ3aJ^m#E
//停止文件下载 #Huvn4x
public void siteStop() :na9PW`TC
{ C%9;~S
bStop = true; @~qlSU&
for(int i=0;i<nStartPos.length;i++) u`O xY
fileSplitterFetch.splitterStop(); P=OHiG\z
#;# V1
4 >at#Zc
} /ZUKt
} 9,sj,A1
//负责部分文件的抓取 "k o?AUt
**FileSplitterFetch.java Lo5itW
*/ !-_0I:m
package NetFox; rzsb(
[kM)K'-
c,:xm=&
import java.io.*; QX1QYwcmG
import java.net.*; ^OnU;8IC
I6,'o)l{_
<,$(,RX
public class FileSplitterFetch extends Thread { `lX |yy"
/GD4GWv :
yZj:Kp+7
String sURL; //File URL O KVIl
long nStartPos; //File Snippet Start Position KuL2X@)}
long nEndPos; //File Snippet End Position 4Z12Z@A#7
int nThreadID; //Thread's ID M_<O'Ii3
boolean bDownOver = false; //Downing is over meA=lg?
boolean bStop = false; //Stop identical i<@6f'Kir
FileAccessI fileAccessI = null; //File Access interface nlOM4fJ(
1JMEniB+9
WwG78b-OA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ri=>evx
{ q\cH+n)C
this.sURL = sURL; F[BJhN*]a
this.nStartPos = nStart; 4|9M8ocR
this.nEndPos = nEnd; $T.we+u
nThreadID = id; FAkjFgUJp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "7mYs)=
} RB`Emp&T
# -e
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public void run() sEP-jEuwG
{ fl#gWAM
while(nStartPos < nEndPos && !bStop) osPJ%I`^
{ G0Q} 1
aw&:$twbM
KCu@5`p
try{ 2oyTS*2u_&
URL url = new URL(sURL); kv{uf$X*ve
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #Mkwd5S|L
httpConnection.setRequestProperty("User-Agent","NetFox"); [%7y !XD
String sProperty = "bytes="+nStartPos+"-"; Fa:fBs{
httpConnection.setRequestProperty("RANGE",sProperty); h U\)CM
Utility.log(sProperty); {>PN}fk2QP
ofH=h
PeT _Ty
InputStream input = httpConnection.getInputStream(); ErIAS6HS'
//logResponseHead(httpConnection); U]jHe
KE!aa&g
qkVGa%^
byte[] b = new byte[1024]; \n$s5i-
int nRead; W/q-^Zkt,9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <+I^K 7
{ Z]kk.@P
nStartPos += fileAccessI.write(b,0,nRead); 2[6>h)
//if(nThreadID == 1) ;43Ye ^=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); exT O#*o
} uTTM%-DMHT
})RT2zw}
Whp;wAz
Utility.log("Thread " + nThreadID + " is over!"); 41Bp^R}^/
bDownOver = true; s3@sX_2
//nPos = fileAccessI.write (b,0,nRead); E^B*:w3
} "h?;)Ye
catch(Exception e){e.printStackTrace ();} RP 'VEJ
} :ZG^`H/X1d
} 6$c,#%Jt*
GO0Spf_Gh
AT Dm$ *
//打印回应的头信息 U ?'$E\
public void logResponseHead(HttpURLConnection con) E`s9SE
{ Rj6:.KEJ
for(int i=1;;i++) GPlAQk
{ :?W {vV
String header=con.getHeaderFieldKey(i); OjO$.ecT
if(header!=null) jyQBx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?|!167/O
Utility.log(header+" : "+con.getHeaderField(header)); /^ *GoB
else 3 d $
break; W _j`'WN/
} Z)}q=NjA
} 7oaa)
5dOA^P@`,M
hDaI@_86
public void splitterStop() h<;kj#qbb
{ f[v~U<\R
bStop = true; *AX)QKQ@
} yem*g1
%SORs(4
GtI]6t
} j$r.&,m
B198_T!
ER,,K._?B
/* +W|MAJtg
**FileAccess.java KY'"Mg^!
*//文件访问(定位，写) 18JhC*in
package NetFox; k<W n
import java.io.*; $mFsf)1]]?
Jg#L8>p1
R7aS{8nn
public class FileAccessI implements Serializable{ {6MLbL{
C {.{>M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _|%pe]St
RandomAccessFile oSavedFile; 2}`Q9?
long nPos; Q)N$h07R
N!" ]e*q
:()(P9?
public FileAccessI() throws IOException pcw!e_"+
{ 86d*
this("",0); |rJ_
} %4QCUc*lr
ONQp-$
KI(9TI*
public FileAccessI(String sName,long nPos) throws IOException xR+=F1y
{ f:iK5g
oSavedFile = new RandomAccessFile(sName,"rw"); Ht^MY
this.nPos = nPos; =w&%29BYq
oSavedFile.seek(nPos); !1<x@%
} ,Yhy7w
$$C5Q;7w!
*UVjN_na5
public synchronized int write(byte[] b,int nStart,int nLen) 7O5`&Z'-
{ $4.mRS97g
int n = -1; 4eb<SNi
try{ JtYc'%OF
oSavedFile.write(b,nStart,nLen); E:BEQ:(~L
n = nLen; S!J.$Y<Ko
} x)<5f|j
catch(IOException e) oH~ZqX.3
{ M (dVY/ i
e.printStackTrace (); I\V33Nd
} Sd'Meebu
$IUP;
I0ycLx
return n; :@g@jcbYq`
} #$V`%2>
=QEg~sD^)s
rC]jz$sle
} ]*a)'k_@[
sQW$P9s c
.K^'Q|?
/* @ [_I|
**SiteInfoBean.java Db({k,P'Y
*/ GEP YSp
package NetFox; 'N,3]Soi
F=
|E@Gsw
public class SiteInfoBean { JA7HO|
6 .DJRY
g-xbb&]
private String sSiteURL; //Site's URL ;@K,>$ur-
private String sFilePath; //Saved File's Path j}8IT
private String sFileName; //Saved File's Name /1++ 8=
private int nSplitter; //Count of Splited Downloading File X?$Eb
0O4'Ts ?
9m56oT'U{
public SiteInfoBean() "hz(A.THi
{//nSplitter的缺省值为5 s<0yQ-=.?N
//default value of nSplitter is 5 q|2{W.P5qi
this("","","",5); ;}IF'ANA
} ~Av]LW
SqY;2:
jM J[6qj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M0o=bYI
{ yZI4%fen
sSiteURL= sURL; ZTd_EY0q
sFilePath = sPath; pfg"6P
sFileName = sName; _J&u{
this.nSplitter = nSpiltter; rPK?pJ
H^"BK-`hs
_%l+v
} pPCxa#OV
$V?zJ:a>L
eG# (9
public String getSSiteURL() M "p6xp/
{ 3hR7 ./
return sSiteURL; ,: w~-
} IC[SJVH;
(d993~|h
QHr 3J
public void setSSiteURL(String value) DLyHC=%{+h
{ ;~z>GJox
sSiteURL = value; 8s8q`_.)(
} uW;Uq=UN
8+a/x#b-
4q@o4C<0
public String getSFilePath() b7v] g]*
{ wd*T"V3
return sFilePath; F-k1yZ?^
} 9 N=KU
[gzU/:
cv:nlq)
public void setSFilePath(String value) 3~I<f^K4
{ ^'QcP5Fv
sFilePath = value; oD{V_/pdx
} A#1aO
f]T1:N*t
g/+M&k$
public String getSFileName() l@1f L%f
{ Djf2ir'
return sFileName; dG7sY O@U
} ~\<ZWU<BE
^.kas7<
qa^x4xZM
public void setSFileName(String value) ;~~Oc
{ a,cDj
sFileName = value; cdU2ph_
} R$,`}@VqZ3
nq/xD;q
?0[%+AD hM
public int getNSplitter() &[cL%pP
{ w])~m1yW
return nSplitter; >4M_jC.
} N_pJE?
q(.%f3(
K1:F{*
public void setNSplitter(int nCount) 2SG|]=
{ ^0{S!fs
nSplitter = nCount; m_rRe\
} .e.vh:Sz
} =5Q;quKu^5
(!X:[Ah*$
u6r-{[W}
/* fY%Sw7ql<
**Utility.java NBMY1Xgj
*/ yvDzxu
package NetFox; 4vqu(w8 L
R<UjhCvx.
aE{b65'Dt
public class Utility { "6KOql3
W]Ph:O^5c
PYz| d
public Utility() $Uewv +
{ |xKB><
;;nmF#
D@ =.4z
} vMRKs#&8
2DV{gF
//线程睡眠 ui 2RTAb
public static void sleep(int nSecond) GMNf#;x
{ r456M-~
try{ _%1.D0<~-E
Thread.sleep(nSecond); 38'H-]8q"
} APc@1="#J
catch(Exception e) *DNH_8m
{ ,+'f unH
e.printStackTrace (); ZN4&:9M
} _cGiuxf #
} _l8oB)
IL%&*B
//日志 W2^eE9
public static void log(String sMsg) aO<d`DTyJ
{ nAts.pVy"
System.err.println(sMsg); V|a59[y?
} 9h0|^ttF
.!6ufaf$
T3?kabbF
public static void log(int sMsg) ;F0A\5I
{ .FMF0r>l
System.err.println(sMsg); T@vVff
} uo%O\}#u9
} \pPq]k
T2(+HI2
^9{ 2
/* KPO((G0&
**TestMethod.java lJYv2EZ
*/ \uPT-M*
package NetFox; H+ M~|Ju7
Ppp&3h[dW)
&Y#9~$V=
public class TestMethod { HE,wEKp
6)bfd^JYn
D3HB`{
public TestMethod() >=Rb:#UM
{ ///xx/weblogic60b2_win.exe jgMWjM6.
try{ EhVnt#`Si
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r}5GJ|p0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1Gqtd^*;
SiteFileFetch fileFetch = new SiteFileFetch(bean); #{?oUg>$
fileFetch.start(); dkn_`j\v
} ^al SyJ`
catch(Exception e){e.printStackTrace ();} hOC,Eo
vcSS+
TX+t
} #UI`G3w<
}}xR?+4A
-OW$
public static void main(String[] args) ~,guw7F
{ :m~lgb<
new TestMethod(); ~g,QwaA[
} T(}da**X
} kN) pi "
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