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)); :\JCxS=EW
} \ a,}1FS
for(int i=0;i<nEndPos.length-1;i++) m$=}nI(H
{ >mX6;6FF
nEndPos = nStartPos[i+1]; 5{oc
} }oA>0Nw$K
nEndPos[nEndPos.length-1] = nFileLength; )WbWp4
} C1e@{>
} ]95VMyN
`BKb60
;cvMNU$fN
//启动子线程 | bRU=dg
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [K$5Rm5
for(int i=0;i<nStartPos.length;i++) $8rnf
{ '(FC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IycZ\^5*-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [#mkTY
nStartPos,nEndPos,i); N|$9v{ j_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~HhB@G!3
fileSplitterFetch.start(); #Zw:&' QB
} Bh'fkW3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @,GL&$Y:W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \Q(a`6U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Lv]%P.=[G
nEndPos = " + nFileLength); "A"YgD#t
// fileSplitterFetch[nPos.length-1].start(); Qy0w'L/@
bf0,3~G,P
o+&Om~W
//等待子线程结束 Gmi?xGn
//int count = 0; J)Y`G4l2@
//是否结束while循环 e)n ,Y
boolean breakWhile = false; y;Cs#eo
F`m}RL]g
babL.Ua8o
while(!bStop) :\P@c(c{^C
{ 8 E\zjT!#\
write_nPos(); PVp>L*|BZ;
Utility.sleep(500); <+g77NL
breakWhile = true; _*6]4\;
tRJ5IX##L
6vsA8u(|V#
for(int i=0;i<nStartPos.length;i++) eZAMV/]jH
{ '0+~]4&}q
if(!fileSplitterFetch.bDownOver) pQBn8H|Y
{ #| _VN %!
breakWhile = false; m..ajYSQ
break; &{.IUg
} Z8ea)_{#
} G|f9l?p
if(breakWhile) cVW7I
break; BYXc 'K
:vb5J33U
wDh]vH[
//count++; TPJF?.le '
//if(count>4) nK :YbLdK,
// siteStop(); ah:["< z<
} b(GV4%
dT*Yv`h
H5x7)1Ir|
System.err.println("文件下载结束！"); H?];8wq$G
} d,Aa8I
catch(Exception e){e.printStackTrace ();} ]|tg`*l!>
} }x`Cnn
"ktuq\a@
h'-4nu;*
//获得文件长度 8C@u+tx
public long getFileSize() /S]RP>cQ
{ ;7z6B|8
int nFileLength = -1; ?'TK~,dG/
try{ isL zgN%
URL url = new URL(siteInfoBean.getSSiteURL()); q7Hf7^a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _x<NGIz
httpConnection.setRequestProperty("User-Agent","NetFox"); g77M5(ME
49Jnp>h
=0d|F 8
int responseCode=httpConnection.getResponseCode(); n8<?<-2
if(responseCode>=400) NSz}
{ iibG$?(
processErrorCode(responseCode); cDY)QUmi
return -2; //-2 represent access is error H9(?yI@Zr#
} EcB !bf
>;I8w(
X?'cl]1?
String sHeader; +_7a/3kh
:,0(aB
~r.R|f]IQ
for(int i=1;;i++) (L*GU7m;
{ jXE:aWQht
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); B>L7UQ6_[
//Utility.log(in.readLine()); gUru=p
sHeader=httpConnection.getHeaderFieldKey(i); "5V;~}=S
if(sHeader!=null) 60!%^O =
{ _eiqs
if(sHeader.equals("Content-Length")) i7.8H*z'
{ (NvjX})eh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T"z<D+pN
break; Jr!BDg
} tdH[e0x B
} gPKf8{#%e
else r& a[?
break; G(a5@9F
} RhE~Rwbx
} [j0[c9.p[
catch(IOException e){e.printStackTrace ();} +=8wZ]
catch(Exception e){e.printStackTrace ();} mF;mJq<d
h+1|.d
skcyLIb
Utility.log(nFileLength); `MSig)V
cuQ!"iH
@vlP)"
return nFileLength; 5j`xSG
} WY!\^| ,
g{yw&q[B=
5)%ahmY
//保存下载信息（文件指针位置） $v@$C4
private void write_nPos() 7{F\b
{ R!j#
try{ OZxJDg
output = new DataOutputStream(new FileOutputStream(tmpFile)); @.W;3|~qc
output.writeInt(nStartPos.length); q~R8<G%YK
for(int i=0;i<nStartPos.length;i++) OS,!`8cw
{ vdq=F|&
// output.writeLong(nPos); \l:R]:w;ZI
output.writeLong(fileSplitterFetch.nStartPos); <==uK>pET
output.writeLong(fileSplitterFetch.nEndPos); :'DyZy2Fd
} {}YA7M:L
output.close(); Da(k>vR@4
} %VO+\L8Fs
catch(IOException e){e.printStackTrace ();} 'Bue*
catch(Exception e){e.printStackTrace ();} h:8P9WhWF
} +06{5-,
<YU?1y?V
^L2d%d\5
//读取保存的下载信息（文件指针位置） Hx gC*-A$/
private void read_nPos() s6|'s<x"j
{ :RnUNz
try{ {6ZSf[Y6B
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fY00
int nCount = input.readInt(); Km(i}:6"
nStartPos = new long[nCount]; ST?{H SCz
nEndPos = new long[nCount]; "] V\Y!
for(int i=0;i<nStartPos.length;i++) A2 +%
{ l}uZxKuYx
nStartPos = input.readLong(); oK\zyNK
nEndPos = input.readLong(); hU$o^ICH
} |0i{z(B
input.close(); [MpWvLP"x
} 7 XxZF43
catch(IOException e){e.printStackTrace ();} i=xh;yb|
catch(Exception e){e.printStackTrace ();} :01d9|#
} ;mU;+~YE
EVqW(|Xg
h< r(:.%!}
private void processErrorCode(int nErrorCode) A'jvm@DvQI
{ iM<$ n2t
System.err.println("Error Code : " + nErrorCode); B5z'Tq1
} ?sk>Mzr
f`hZb
=VD],R)
//停止文件下载 >_2~uF@pb
public void siteStop() ;TJpD0
{ n*7^lAa2
bStop = true; +c~&o83[
for(int i=0;i<nStartPos.length;i++) ]:gW+6w"C
fileSplitterFetch.splitterStop(); Ok_}d&A
w#b@6d
w,p'$WC*
} B.; qvuM~
} H'k}/<%Q
//负责部分文件的抓取 \n[kzi7
**FileSplitterFetch.java VCWW(Y1Fd
*/ I<#X#_YP
package NetFox; $+Ze"E
Lk !)G'42
-V}oFxk]q
import java.io.*; nFQuoU]ux
import java.net.*; JVIFpN"`
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G(7%*@SX
public class FileSplitterFetch extends Thread { iO$87!
tB4mhX|\
$P{`-Y }a
String sURL; //File URL "-=fi 'D
long nStartPos; //File Snippet Start Position =Dq&lm,n
long nEndPos; //File Snippet End Position _qa]T'8
int nThreadID; //Thread's ID q!c=f!U?\l
boolean bDownOver = false; //Downing is over zGtJ@HbB
boolean bStop = false; //Stop identical _Tj&gyS
FileAccessI fileAccessI = null; //File Access interface 6M >@DRZ'|
4Fft[S(
]Ucw&B*@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException CGi;M=xr
{ v@=qVwX
this.sURL = sURL; @-sWXz*W
this.nStartPos = nStart; ,>-jZtm
this.nEndPos = nEnd; !h.hJt
nThreadID = id; p^8a<e?f~f
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9O 'j+?(`@
} 8oJl ]
[#Qf#T%5h
vaB ql(?'2
public void run() 4 . 7X*1
{ F@?-^ E@
while(nStartPos < nEndPos && !bStop) inaO{ny y
{ S"&Gutu3o
"J"=<_?
R,BJr y
try{ Z[nHo'
URL url = new URL(sURL); $U_(e:m}f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (I$%6JO:
httpConnection.setRequestProperty("User-Agent","NetFox"); yUnV%@.
String sProperty = "bytes="+nStartPos+"-"; 7W)W9=&BT
httpConnection.setRequestProperty("RANGE",sProperty); dx@dnWRT,
Utility.log(sProperty); q}Q G<%VR
G!Brt&_'
3Q$4`p;
InputStream input = httpConnection.getInputStream(); ;5ki$)v"
//logResponseHead(httpConnection); =Ydrct
>=0]7k;
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byte[] b = new byte[1024]; gxl7jY
int nRead; _RaE:)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c-k3<|H`
{ ;}E}N:A
nStartPos += fileAccessI.write(b,0,nRead); un 5r9
//if(nThreadID == 1) A`uHZCwJ5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r &.~ {
} JN/=x2n.
UfX~GC;B
zcP=+Y)YA
Utility.log("Thread " + nThreadID + " is over!"); c]uieig0~
bDownOver = true; tpGT~Y(
//nPos = fileAccessI.write (b,0,nRead); ye.6tlW
} oks;G([
catch(Exception e){e.printStackTrace ();} @%,~5{Ir
} on7 n4
} v":q_w<k
:6Nb,Hh~
1%v6d !
//打印回应的头信息 |<u+Xi ~
public void logResponseHead(HttpURLConnection con) %'1iT!g8
{ KVOV<uDCj
for(int i=1;;i++) m#UQ,EM
{ Pdf-2 Tx
String header=con.getHeaderFieldKey(i); ~LuGfPO^
if(header!=null) 6=/sEzS'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xS1|t};
Utility.log(header+" : "+con.getHeaderField(header)); v7"VH90`!
else 56)!&MF
break; +E</A:|}S
} *V kaFQZ$,
} Ye3o}G9z
v/ N[)<
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public void splitterStop() zu1"`K3b
{ '6M6e(
bStop = true; 486\a
} X\m\yv}}
/F;2wT;
&ww-t..
} xfeED^?
VFf;|PHS
Q2 !GWz$
/* f5*qlQJFz\
**FileAccess.java ZR\N~.
*//文件访问(定位，写) C7dq=(p&
package NetFox; Q#3}AO
import java.io.*; @4y?XL(n
4MPy}yT*
WOn<;'}M&
public class FileAccessI implements Serializable{ G[ U5R?/
$l*?Ce:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )8C`EPe
RandomAccessFile oSavedFile; m538p.(LIR
long nPos; I$.lFQ%(
GKFRZWXdT
7K.75%}
public FileAccessI() throws IOException nms[No?
{ nod&^%O"
this("",0); rNk'W,FU
} #r#[&b
]jD\4\M}
/O:4u_
public FileAccessI(String sName,long nPos) throws IOException @ ;!IPiU
{ R%szN.cI
oSavedFile = new RandomAccessFile(sName,"rw"); oYN"L
this.nPos = nPos; _\4#I(
oSavedFile.seek(nPos); :2KHiT5
} =H)]HxEEM
d'96$e o~
[QxP9EC
public synchronized int write(byte[] b,int nStart,int nLen) #A5X,-4G
{ UE^o}Eyg
int n = -1; =Q<VU/
try{ aM $2lR])J
oSavedFile.write(b,nStart,nLen); ')v,<{
n = nLen; H[hJUR+#
} {`D]%eRO
catch(IOException e) ~Y`ys[Z m
{ Ibz9juY
e.printStackTrace (); yo[Sh6r/9b
} |^-D&C(Eu
7nT|yL?
`+n0a@BVB
return n; &j:e<{@
} .L^*9Y0)
WkiT,(i
6agq^wI
} 6#Z]yk+p
lPZ>#
FQ4R>@@5
/* 26/<\{q~
**SiteInfoBean.java a"-uJn
*/ `"65 _?B i
package NetFox; Z5v_- +K
r\"R?P$y|
b[:,p?:@
public class SiteInfoBean { %JBLp xnq
ta{24{?M\
eOb--@~8
private String sSiteURL; //Site's URL rY(7IX
private String sFilePath; //Saved File's Path ~T;:Tg*
private String sFileName; //Saved File's Name PR"x&JG@
private int nSplitter; //Count of Splited Downloading File fof}I:vO
Y#c439&
MtL<)?HQ
public SiteInfoBean() %j^QK>%
{//nSplitter的缺省值为5 @K!JE w\
//default value of nSplitter is 5 pG"wQ
this("","","",5); nT> v
} ke2dQ^kc4
9xbT?$^
C"kfxpCi
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A4,%l\di<
{ KWo Ps%G
sSiteURL= sURL; R{c~jjd
sFilePath = sPath; =l:V9u-I^
sFileName = sName; ?Ojv<L-f.:
this.nSplitter = nSpiltter; G%HG6
}kt%dDU
P@@MQ[u?!.
} *jhgCm
'nPI zK<v
=-Hhm($n
public String getSSiteURL() .I~:j`K6
{ q>(?Z#sB
return sSiteURL; GcN}I=4|
} Lx>[`QT
4AEw[(t
'GezIIaH
public void setSSiteURL(String value) ,oH\rrglf
{ d,?D '/
sSiteURL = value; )A*53>JV
} c<Cf|W
p^ (Z
w#)u+^-
public String getSFilePath() T(u;<}e@[
{ +JYb)rn$^
return sFilePath; tRI<K
} /TsXm-g#
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Iq%<E:+GL
public void setSFilePath(String value) $yi:0t8t
{ G0!6rDu2,
sFilePath = value; Jf4` 2KN\
} q`PA~C];
1|8Bv0-b
b;D
public String getSFileName() 7yu-xnt3s
{ B?&0NpVD
return sFileName; W#!AZ!
} WYF8?1dt +
FR6 W-L
6IRRRtO(
public void setSFileName(String value) p#qla'
{ MS#"TG/)
sFileName = value; A-1KTD
} z&0[F`U
&Ih}"
<_8bAO8\
public int getNSplitter() )SP"V~^Wn
{ 'y!qrmMRr
return nSplitter; 5|0/$ SWd*
} 6p }a!
+x{o
>}f!. i
public void setNSplitter(int nCount) H.|I|XRG/
{ BegO\0%+
nSplitter = nCount; MR,I`9Pe
} NV?x<LNWd
} e46`"}r
|pZ7k#%
]8wm1_qV
/* PeIi@0vA
**Utility.java Lk]|;F-2i
*/ 9h+Hd&=
package NetFox; ,j>FCj>
@7"n X
9=$pV==
public class Utility { JAKs [@:
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nygGI_[l
public Utility() HD#>K 7
{ ;39a`
zd2_k 9
0kCo0{+n
} $k)K}U
h/A\QW8Sd
//线程睡眠 5Q%)|(U'
public static void sleep(int nSecond) U"|1@W#
{ =D0d+b6
try{ M 2| k.
Thread.sleep(nSecond); b=S"o )>
} uSYI X
catch(Exception e) Y*pXbztP
{ V?*fl^f
e.printStackTrace (); v+xrnz
} $X;OK
} vh&~Y].W Y
KsTGae;ds
//日志 q p}2
public static void log(String sMsg) 72RTEGy
{ h{o,*QL
System.err.println(sMsg); `+(n+QS _
} bxPa|s?
{q$U\y%Rq
w5y.kc;
public static void log(int sMsg) e8):'Cb
{ J V}7c$_
System.err.println(sMsg); 8IL5:7H8
} %"c;kvw
} Mu:zWLM*M
?r(vXq\
&S*{a
/* |O)ZjLx
**TestMethod.java B>'J5bZsw
*/ mpD.x5jm<
package NetFox; h`! 4`eI
uL7}JQ,
gA_oJW4_
public class TestMethod { -">Tvi4
g qORE/[
dHOH]x
public TestMethod() o$->|k
{ ///xx/weblogic60b2_win.exe 8zRw\]?
try{ 8?m=Vw<kIZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B!`.,3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); BQUYT/$(
SiteFileFetch fileFetch = new SiteFileFetch(bean); a'-xCV|^
fileFetch.start(); r UZN$="N
} #p;<X|Hc}8
catch(Exception e){e.printStackTrace ();} 2=fLb7
7}\AhQ, S
[-#1;!k
} OY|9V
)40YA\V
IeChz d
public static void main(String[] args) ,1|=_M31
{ i)cG
new TestMethod(); VIGLl'8p
} =&-.]|t
} @o@SU"[?_
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