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)); hZ&KE78?
} @@65t'3S
for(int i=0;i<nEndPos.length-1;i++) +7_qg i7:
{ iC"iR\Qu
nEndPos = nStartPos[i+1]; ){^J8]b7#
} WtT;y|W
nEndPos[nEndPos.length-1] = nFileLength; 8=8hbdy;
} lx)^wAO4
} @X==[gQ
q+ax]=w
MpV<E0CmE
//启动子线程 /bo}I-<2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~ao:9ynY
for(int i=0;i<nStartPos.length;i++) YQBLbtn6(
{ >3 o4 U2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6(n0{A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), djd/QAfSC
nStartPos,nEndPos,i); )U/jD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VYk:c`E
fileSplitterFetch.start(); J9^NHU
} #Hw|P
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Cf% qap#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); YT\`R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U3(+8}Q
nEndPos = " + nFileLength); =[B\50]
// fileSplitterFetch[nPos.length-1].start(); I/E9:
7^L
).~ "
//等待子线程结束 N/4E ~^2
//int count = 0; 55Ss%$k@
//是否结束while循环 `4Yo-@iVP
boolean breakWhile = false; 9LR=>@Z
C6!F6Stn]g
Et=Pr+Q{c
while(!bStop) JZ5k3#@e
{ N\{"&e
write_nPos(); W06aj ~7Z
Utility.sleep(500); ?cU,%<r
breakWhile = true; |]\zlH"w
,i>`Urd
Bf{u:TCK
for(int i=0;i<nStartPos.length;i++) = Xgo}g1
{ "Q?+T:D8|
if(!fileSplitterFetch.bDownOver) HDe\Oty_
{ a_?sJ
breakWhile = false; |T:R.=R$~
break; -|>~I#vY
} G m~ ./-
} 5.rAxdP
if(breakWhile) $dC`keQM>9
break; GppCrQ%Ra|
=LW!$p
c_8&4
//count++; <WXVUEea
//if(count>4) e~)[I!n
// siteStop(); 3>O|i2U
} %:3XYO.w-
09kR2(nsW/
ww2mL <B
System.err.println("文件下载结束！"); +%dXB&9x|Z
} >0^<<=m
catch(Exception e){e.printStackTrace ();} EX,>V,.UV
} wh$bDTCj
U>S
q}U+BTCZ
//获得文件长度 7|,L{~
public long getFileSize() VfU"%0x
{ (r|m&/
int nFileLength = -1; 05d0p|},
try{ F8pA)!AH
URL url = new URL(siteInfoBean.getSSiteURL()); =uP? ?E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t"=5MaQk-
httpConnection.setRequestProperty("User-Agent","NetFox"); )+.=z
3?Pg ;
mjeJoMvN)H
int responseCode=httpConnection.getResponseCode(); `Ba]i)!
if(responseCode>=400) #g{R+#fm
{ -FZC|[is
processErrorCode(responseCode); fi?4!h
return -2; //-2 represent access is error FnvpnU",
} GJ9>i)+h;
zWY988fX0
Exb64n-_=
String sHeader; R%UTYRLUn
Gwd38
#p}GWS)
for(int i=1;;i++) O}M-6!%<,
{ +,e#uuj$p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4@9Pd &I
//Utility.log(in.readLine()); =j.TDv'^nd
sHeader=httpConnection.getHeaderFieldKey(i); t3<MoDe7`r
if(sHeader!=null) 3$?6rMl@y
{ cBxGGggB
if(sHeader.equals("Content-Length")) !M^O\C)
{ Tmzbh 9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); nI:M!j5s`
break; 5(>=};r+
} bRAD_
} /,\V}`Lx"
else uw;Sfx,s
break; VF`!ks
} v,w af`)J
} Giyh( DL
catch(IOException e){e.printStackTrace ();} yE}\4_0I/
catch(Exception e){e.printStackTrace ();} &8$v~
T$;S
';C'9k<P:
Utility.log(nFileLength); 25>R^2,LiE
* %D_\0;
%"WENa/t
return nFileLength; ifDWN*k6
} '=dQ$fs
h;V4|jM
7FC!^)x1
//保存下载信息（文件指针位置） ,Lig6Z`
private void write_nPos() |ADf~-AY
{ wJC[[_"3 I
try{ P$EiD+5#z
output = new DataOutputStream(new FileOutputStream(tmpFile)); jVff@)_S
output.writeInt(nStartPos.length); lV\iYX2#
for(int i=0;i<nStartPos.length;i++) 9nFL70
{ VZ9 p "
// output.writeLong(nPos); N/tcW
output.writeLong(fileSplitterFetch.nStartPos); E)-;sFz
output.writeLong(fileSplitterFetch.nEndPos); )re<NE&M
} f,G*e367:
output.close(); [qc1 V%g
} ~F"S]
catch(IOException e){e.printStackTrace ();} j iKHx_9P
catch(Exception e){e.printStackTrace ();} ]?6wU-a
} 8iIp[9~=
/.]u%;%r[
2%@tnk|@
//读取保存的下载信息（文件指针位置） &5W;E+Pub
private void read_nPos() T}fo
{ &gCGc?/R#
try{ P~a@{n*8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q(& @ra!{
int nCount = input.readInt(); _dKMBcl)E
nStartPos = new long[nCount]; 8T1`9ITl:
nEndPos = new long[nCount]; T5:Q_o]
for(int i=0;i<nStartPos.length;i++) |Y3w6!$
{ XvI~"}
nStartPos = input.readLong(); 9pLe8D
nEndPos = input.readLong(); x Lan1V
} OAXA<
input.close(); IxbQ6
} 7_\G|Zd
catch(IOException e){e.printStackTrace ();} !v8R(
catch(Exception e){e.printStackTrace ();} $Cz2b/O
} 4R'CLN |t
a>47k{RSzE
m.lR]!Y=w
private void processErrorCode(int nErrorCode) ;W- A2g
{ 2 7)IfE
System.err.println("Error Code : " + nErrorCode); gmVN(K}SR5
} a2P)@R
;EBKzB
{o~TbnC
//停止文件下载 _r:Fmn_%-
public void siteStop() ad}8~6}_&
{ 71{Q#%5U~
bStop = true; )U~|QdZ
for(int i=0;i<nStartPos.length;i++) %9cT#9!7
fileSplitterFetch.splitterStop(); W&hW N9iR
m7^f%<l
,5W7a
} 8?Rp2n*o
} v]EMJm6d|
//负责部分文件的抓取 7Fj8Mp|
**FileSplitterFetch.java Y_CYx
*/ oJA_"xp
package NetFox; d*8*9CpO:
ny KfM5s_
|enLv12Gm
import java.io.*; w"{DLN[Qw
import java.net.*; LK}g<!o(
6Z|h>H5a
f2e;N[D
public class FileSplitterFetch extends Thread { D$>!vD'
8i',~[
I8XP`Ccq
String sURL; //File URL qur2t8gnxq
long nStartPos; //File Snippet Start Position lie,A
long nEndPos; //File Snippet End Position f#z:ILG=
int nThreadID; //Thread's ID Ch]d\GM
boolean bDownOver = false; //Downing is over e@P(+.Ke
boolean bStop = false; //Stop identical ~cc }yDe
FileAccessI fileAccessI = null; //File Access interface Y"lEMY
ps'_Y<@
Krae^z9R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ao\P|K9MyL
{ YrnC'o`
this.sURL = sURL; DgT]Nty@b
this.nStartPos = nStart; 5Npxs&Ea
this.nEndPos = nEnd; a,w|r#x]
nThreadID = id; ;`oK5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;t0q ?9
} NVRzthg%c_
T +vo)9w
x'g4DYl
public void run() -J3~j kf
{ (RFH.iX
while(nStartPos < nEndPos && !bStop) %*Ex2we&
{ 4s7 RB
pg%(6dqK4
,ayEZ#4.m
try{ =mXC,<]
URL url = new URL(sURL); $wAR cS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ba[,9l[
httpConnection.setRequestProperty("User-Agent","NetFox"); iyn9[>je
String sProperty = "bytes="+nStartPos+"-"; Xf4~e(O
httpConnection.setRequestProperty("RANGE",sProperty); =803rNe
Utility.log(sProperty); +j{Cfv$do
!JXiTI!
1 !_p
InputStream input = httpConnection.getInputStream(); 1r=cCM
//logResponseHead(httpConnection); A,F~*LXm
:(]fC~G~
pq`uB
byte[] b = new byte[1024]; ,]EhDW6
int nRead; F`7v
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g `s|]VNt
{ 0!,uo\`
nStartPos += fileAccessI.write(b,0,nRead); =.z;:0]'n
//if(nThreadID == 1) KRL.TLgq)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j{lurb)y
} Z5Lmg
fHd[8{;P:
%rrA]\C'
Utility.log("Thread " + nThreadID + " is over!"); HF0G=U}i
bDownOver = true; l Xa/5QKC
//nPos = fileAccessI.write (b,0,nRead); wF`Y ,@
} |RL#BKC`
catch(Exception e){e.printStackTrace ();} t.8r~2(?
} V22z-$cb
} sQ`G'<!
6C VH)=%
dGp7EB`
//打印回应的头信息 jRjeL'"G
public void logResponseHead(HttpURLConnection con) "r46Rfa
{ RiQ]AsTtl
for(int i=1;;i++) %)7t2D
{ HaVhdv3L
String header=con.getHeaderFieldKey(i); jMn,N9Mf
if(header!=null) yMWh#[phH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e' M&Eh
Utility.log(header+" : "+con.getHeaderField(header)); Imv#7{ndq
else @$jV"Y
break; cTGd<
} Os<E7l zqO
} F6}RPk\=i
t~(jA9n
p=:Vpg<!
public void splitterStop() ZGZNZ}~#
{ #DgHF*GG+>
bStop = true; e%cTFwX?n
} 3SIqod;%
+4-T_m/W/
U,P>P+\@
} Ms|c"?se
'yPKQ/y$x
l(NQk> w
/* XSC=qg$
**FileAccess.java Z$/76
*//文件访问(定位，写) d~~kJKK
package NetFox; e4` L8
import java.io.*; 3A`Gx#
YTyrX
5;}W=x^$a
public class FileAccessI implements Serializable{ EQ273sdK
i*=~mO8E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 os{ iY
RandomAccessFile oSavedFile; ol"|?*3q
long nPos; U1r]e%df)
~Fuq{e9`
XY| y1L 3[
public FileAccessI() throws IOException 44}5o
{ jM\{*!7b
this("",0); &1Ndi<Y^
} _94 W@dW
eMRH*MyD
0FOB5eBR
public FileAccessI(String sName,long nPos) throws IOException ! $$>D"
{ sm-[=d%@L
oSavedFile = new RandomAccessFile(sName,"rw"); 83c2y;|8
this.nPos = nPos; QP%_2m>yhl
oSavedFile.seek(nPos); r+bGZ
} M?lh1Yu"
}R}+8
#Kb /tOp1
public synchronized int write(byte[] b,int nStart,int nLen) >SI'Q7k
{ M,fL(b;2
int n = -1; n.+'9Fj
try{ wS}c\!@<,
oSavedFile.write(b,nStart,nLen); o^/ #i`)
n = nLen; |@AXW
} Y_CVDKdcY
catch(IOException e) V^,gpTyv*
{ X8*g#lO?
e.printStackTrace (); -F7F 6!s
} w5 .^meU
G[mqLI{q
#r9+thyC
return n; <(KCiM=E$
} -iiX!@
_uO$=4Sd
,m<YSMKX
} AU\=n,K7
*Y(59J2
Y]([K.I=
/* 1w=.vj<d8
**SiteInfoBean.java NVb}uH*i
*/ 2{h2]F
package NetFox; 8b?nr;@
x/O;8^b
SxYz)aF~
public class SiteInfoBean { {<ShUN
Rv&"h_"t
jg?UwR&
private String sSiteURL; //Site's URL 4"2%mx:
private String sFilePath; //Saved File's Path bX$z)]KKu
private String sFileName; //Saved File's Name U"7o;q
private int nSplitter; //Count of Splited Downloading File X_2N9$},
)P(S:x'b0
K(?V]Mxl6
public SiteInfoBean() Q("m*eMRt
{//nSplitter的缺省值为5 uU 7 <8G
//default value of nSplitter is 5 WPRk>j
this("","","",5); hq7f"`
} G0 EXgq8
P7-k!p"
BsFO]F5mmX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9:{<:1?
{ I#MPJ@*WT
sSiteURL= sURL; :Tpf8
sFilePath = sPath; z[f]mU
sFileName = sName; *W8n8qG%T
this.nSplitter = nSpiltter; ZhY{,sy?QO
0i\>(o
Sl8+A+
} BHY-fb@R]H
MZ"V\6T]
6>)fNCe`
public String getSSiteURL() hA ){>B<;
{ o:#jvi84F
return sSiteURL; eF%M2:&c;
} SPV+ O{
PaSwfjOnqr
MQP9^+f)O?
public void setSSiteURL(String value) Gt*<Awn8
{ :z8/iD y
sSiteURL = value; zh2<!MH
} f$>_>E
q(qm3OxYo
c= t4 gf
public String getSFilePath() c6F?#@?
{ }p?,J8=-
return sFilePath; l?)>"^
} Wq3PN^
KRxJ2
G|jHic!
public void setSFilePath(String value) >l 0aME@-0
{ m^oG9&";
sFilePath = value; LhAN( [
} 1vq2`lWpx
9C \}bT
]lA}5
public String getSFileName() 2@MpWj4
{ rS>.!DiYr,
return sFileName; 1#N`elm
} 7D<Aa?cv_l
"=Z=SJ1D
h~Ir=JV
public void setSFileName(String value) |$/#,Dv7
{ drAJ-ii
sFileName = value; !!L'{beF
} h.?<(I
jlb8<xIC]
_i ztQ78
public int getNSplitter() p8 S~`fjV
{ N_ ODr]L
return nSplitter; Dl.<(/
} Vb?wwx7=
/HUT6B
2(!W 9#]
public void setNSplitter(int nCount) fP<==DK
{ }N9PV/a
nSplitter = nCount; %S^ke`MhF
} 5:38}p9`
} 7d.H8C2
$E[O}+L$#
qf K gNZ
/* .~I:Hcf/
**Utility.java :Jyr^0`J
*/ 8o:h/F
package NetFox; (;g/wb:
n5"i'o{w
hD#Mhy5h
public class Utility { ~<u\YIJ
c@,1?q1bv
roZn{+f
public Utility() F$i50s
{ WS&a9!3;
CHS}tCfos>
y=9fuGL6
} 9+(6/<
KOR*y(*8
//线程睡眠 d3a!s
public static void sleep(int nSecond) 0<uL0FOT
{ KYkS^v
try{ rk%pA-P2
Thread.sleep(nSecond); %l%ad-V
} ih("`//nP
catch(Exception e) a:P+HU:
{ %d:cC:`
e.printStackTrace (); vZQraY nJ
} R,.qQF\*
} yuq o ^i
lw8t#_P
//日志 Jm=3%H
public static void log(String sMsg) @=g{4(zR^
{ DCa=o
System.err.println(sMsg); ;]R5:LbXS
} KKk<wya&O
F+5 5p8
, MqoX-+
public static void log(int sMsg) rLeQBp'
{ 43=)akJi
System.err.println(sMsg); V,Bol(wY
} a-#$T)mmfj
} L
dM}c-=w`
u=PLjrB~}
/* 8fQfu'LyjY
**TestMethod.java >`WQxkpy
*/ - ]/=WAOK
package NetFox; Wt5pK[JV
>t9DI
2ETv H~23
public class TestMethod { MYJMZ3qBi
1e9~):C~W
KWYjN h#*
public TestMethod() 3it*l-i\
{ ///xx/weblogic60b2_win.exe ,y0 &E8Z
try{ kxrYA|x
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SPe%9J+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cAx$W6S
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,ZYPffu<*
fileFetch.start(); }]1C=~lC
} nql{k/6
catch(Exception e){e.printStackTrace ();} 3 %BI+1&T_
F1}d@^K 7d
o]]tH
} \ %xku:
a$iDn_{
D0_CDdW%7
public static void main(String[] args) T#e|{ZCbq
{ N3Q .4? z9
new TestMethod(); Z>/ *q2
} CZ^ ,bad
} ]T40VGJ:h
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