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)); FSs$ ] d;
} &Ld8Z9IeFp
for(int i=0;i<nEndPos.length-1;i++) WI_mJ/2
{ ]_8I_VcQ
nEndPos = nStartPos[i+1]; `0|&T;7
} L$Ar]O)
nEndPos[nEndPos.length-1] = nFileLength; JSK5x(GlH
} -U[`pUY?f
} y|{?>3
\'Kj.EO{?$
#`0z=w/)
//启动子线程 ya g
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; TR_oI<xB2
for(int i=0;i<nStartPos.length;i++) ItE~MJ5p
{ a' o8n6i
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =[os<+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h\\2r>
nStartPos,nEndPos,i); Q$/FgS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "0zXpQi,B
fileSplitterFetch.start(); M|e n>P
} (Gc`3jJ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =3dbw8I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <|Eby!KXR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |S`yXsg
nEndPos = " + nFileLength); 9R"N#w.U]
// fileSplitterFetch[nPos.length-1].start(); <L/vNP
sNmC#,
p+UHJ&
//等待子线程结束 <JM%Kn )
//int count = 0; F6]!?@
//是否结束while循环 4~YQ\4h=
boolean breakWhile = false; Prz+kPP
P Xn>x8z
1'm`SRX#e
while(!bStop) PFgjWp"Y
{ l'".}6S
write_nPos(); QYw4kD}
Utility.sleep(500); >E ;o"
breakWhile = true; /M*\t.[ 46
8;f<qu|w
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for(int i=0;i<nStartPos.length;i++) o\;"|O}
{ N<"6=z@w+
if(!fileSplitterFetch.bDownOver) dQ`ZrWd_U
{ )wzs~Fn/
breakWhile = false; c&?a,fpb
break; tSc>@Q_|
} r9a!,^}F
} '# IuY
if(breakWhile) !vVjZ
break; p2DNbY\]
as|c`4r\O
Y1aF._Z
//count++; `=$jc4@J
//if(count>4) hIo S#]
// siteStop(); ^npS==Y]!.
} I+j|'=M
fZ~kw*0*
vp75u93
System.err.println("文件下载结束！"); 2n;;Tso"
} \{=`F`oB=
catch(Exception e){e.printStackTrace ();} xgqv2s>L
} uQtk|)T E
dzE Q$u/I
?$@KwA
//获得文件长度 E(3+o\w
public long getFileSize() &G|jzXE
{ 6O@ ^`T
int nFileLength = -1; m#'rI=}!
try{ |U$de2LF
URL url = new URL(siteInfoBean.getSSiteURL()); ecqz@*d&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HZ<f(
httpConnection.setRequestProperty("User-Agent","NetFox"); ^r$iN %&~
""v`0OP&J
c]!D`FA*K
int responseCode=httpConnection.getResponseCode(); R ms01m>Y
if(responseCode>=400) s.I1L?s1w?
{ pM'IQ3N
processErrorCode(responseCode); 5v>{Z0TE[6
return -2; //-2 represent access is error &J/4J
} 3auJ^B}
9H, &nET
CBnouKc:
String sHeader; .Lr)~
~eV!!38 J
CNRU"I+jU
for(int i=1;;i++) xAd>",=~
{ s3_e7D ^H
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); PVS<QN%
//Utility.log(in.readLine()); )4L%zl7
sHeader=httpConnection.getHeaderFieldKey(i); :_QAjU
if(sHeader!=null) ['Y+z2k
{ uJ/?+5TU
if(sHeader.equals("Content-Length")) 5ih"Nds[H
{ !ga(L3vf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :OQ:@Yk
break; $,QpSK`9i
} bu"68A;>
} ic0v*Y$
else ,+f0cv4
break; m~j\?mb{+
} 7=p-A_X
} 'D0X?2
catch(IOException e){e.printStackTrace ();} M$]O=2h+2
catch(Exception e){e.printStackTrace ();} Neo^C_[vN
rv%ye H
x#j\"$dla
Utility.log(nFileLength); *n*N|6+
PZ!dn%4jy
#?$'nya*u
return nFileLength; X#kjt)W
} ZP63Alt
o,Tr^e$
_+Jf.n20
//保存下载信息（文件指针位置） EB29vHAt~
private void write_nPos() dp[w?AMhM9
{ e:GgA
try{ ^`jZKh8)h
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;&W;
output.writeInt(nStartPos.length); fr'huvc
for(int i=0;i<nStartPos.length;i++) Hr<C2p^a
{ -wfRR>)d
// output.writeLong(nPos); @( n^S?(
output.writeLong(fileSplitterFetch.nStartPos); 16[-3cJ T
output.writeLong(fileSplitterFetch.nEndPos); :B*vkwT
} ^QXw[th!d
output.close(); C7jc6(>m
} JwI`"$>w
catch(IOException e){e.printStackTrace ();} ANFg]g.Az
catch(Exception e){e.printStackTrace ();} 7dlKdKH
} C'8!cPFVv
EOBs}M;
sR>`QIi(a
//读取保存的下载信息（文件指针位置） m,@1LwBH
private void read_nPos() orB8Q\p'
{ KCJN<
try{ L*UV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~gfA](N
int nCount = input.readInt(); :zj9%4A
nStartPos = new long[nCount]; 2-$bh
nEndPos = new long[nCount]; I NPYJ#%
for(int i=0;i<nStartPos.length;i++) ^)hAVf~E
{ @m/;ZQ
nStartPos = input.readLong(); #j^('K|
nEndPos = input.readLong(); >9.5-5"
} Wiq{wxe
input.close(); 4{*tn"y
} |ilv|UV
catch(IOException e){e.printStackTrace ();} L8bI0a]r"*
catch(Exception e){e.printStackTrace ();} OBI+<2`Oc
} EREolCASb
+-H}s`
43J\8WBn@
private void processErrorCode(int nErrorCode) $c@w$2
{ 83 i1
System.err.println("Error Code : " + nErrorCode); `sk!C7%
} q6C6PPc
m1hW<
u(1J=h
//停止文件下载 2<[eD`u
public void siteStop() N>A{)_k3
{ 9@#h}E1$
bStop = true; QM[A;WBr7
for(int i=0;i<nStartPos.length;i++) })o~E
fileSplitterFetch.splitterStop(); q:Y6fbt<7
CYPazOfj
2ec$xms
} t_I\P.aMA
} *t#s$Ga
//负责部分文件的抓取 A$%Q4jC}
**FileSplitterFetch.java >Lw}KO`
*/ \);.0
package NetFox; VX^o"9Ntl
49+ >f
p{ @CoOn
import java.io.*; )YzHk ;(
import java.net.*; XMN?;Hj>
fg9?3x Z
JJ/1daj
public class FileSplitterFetch extends Thread { 0T9@,scY
Dd!Sr8L[
f{y]
String sURL; //File URL /OQK/ t63
long nStartPos; //File Snippet Start Position $^W-Wmsz
long nEndPos; //File Snippet End Position F . K2
int nThreadID; //Thread's ID "t[M'[ `C
boolean bDownOver = false; //Downing is over On{~St'V
boolean bStop = false; //Stop identical !;o\5x<'$O
FileAccessI fileAccessI = null; //File Access interface 24T@N~\g
QU^/[75Ea0
xab]q$n]k
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *2JH_Cj`
{ o {=qC:b
this.sURL = sURL; ?xtt7*'D
this.nStartPos = nStart; kAZC"qM%i
this.nEndPos = nEnd; *:=];1O
nThreadID = id; UGhW0X3k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }Vvsh3
} "sF Xl
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Qs|OG
public void run() _Kc1
{ )\{'fF
while(nStartPos < nEndPos && !bStop) IK*oFo{C=K
{ Y%<`;wK=^
UF@IBb}0
#*!+b
try{ t*{,Gk
URL url = new URL(sURL); ![^EsgEB*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %ZujCZn
httpConnection.setRequestProperty("User-Agent","NetFox"); _9D|u<D
String sProperty = "bytes="+nStartPos+"-"; 9pWi.J
httpConnection.setRequestProperty("RANGE",sProperty); #F_'}?09%
Utility.log(sProperty); Dn~Z SrJ
f>.4-a?
[f<"p[
InputStream input = httpConnection.getInputStream(); q1YLq(e
//logResponseHead(httpConnection); U?bG`. X
c]A Y
IE&_!ce
byte[] b = new byte[1024]; ?22d},.
int nRead; X?tj$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o_iEkn
{ pG/ NuImA
nStartPos += fileAccessI.write(b,0,nRead); ]]>nbgGn#
//if(nThreadID == 1) tf4*R_6;1$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ecn}iN
} :/+>e IE
B;VH`*+X
>&bv\R/
Utility.log("Thread " + nThreadID + " is over!"); Rr%tbt.sE
bDownOver = true; $bk>kbl P
//nPos = fileAccessI.write (b,0,nRead); \X&]FZ(*
} @u,+F0Yd
catch(Exception e){e.printStackTrace ();} KwS`3 6:
} zQ,f5x
} m&Lt6_vi
Z.!g9fi8>
#nKRTb+{
//打印回应的头信息 g^1r0.Sp{8
public void logResponseHead(HttpURLConnection con) S|HY+Z6n'
{ Ba<ngG !
for(int i=1;;i++) /T,zZ9=
{ zVdKYs i^
String header=con.getHeaderFieldKey(i); l1&5uwuF
if(header!=null) 4<u;a46Z#M
//responseHeaders.put(header,httpConnection.getHeaderField(header)); : (cb2j(C
Utility.log(header+" : "+con.getHeaderField(header)); :3v9h^|+
else V|TA:&:7
break; z;J
} H ZPcd_(
} L^lS^P
GE@uOJ6H
Qh^R Ax
public void splitterStop() /mc*Hc8R8
{ dgXg kB'
bStop = true; ]GNh)
} I-,>DLG
i<mevL
3c b[RQf
} ozU2
/J;;|X#P
{B3(HiC
/* 6#E7!-u(-
**FileAccess.java yr5NRs
*//文件访问(定位，写) aVP5%
package NetFox; ,(P %z.P@
import java.io.*; *%X.ym'
T8U[xu.>
l8^y]M
public class FileAccessI implements Serializable{ (v!mR+\x
x@Y|v@}BE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gV|Y54}T
RandomAccessFile oSavedFile; |~eY%LB
long nPos; L;3aZt,#O
[<yz)<<
PB+\jj
public FileAccessI() throws IOException G.Tpl-m
{ !3h{lEB
this("",0); Je^Y&a~
} *<r%aeG$em
|CwG3&8
N+NK`
public FileAccessI(String sName,long nPos) throws IOException BhLZ7*
{ ^#;RLSv
oSavedFile = new RandomAccessFile(sName,"rw"); //<:k8
this.nPos = nPos; p5-<P?B
oSavedFile.seek(nPos); `gI~|A4
} pw3(t
S;8.yj-
6}ftBmv
public synchronized int write(byte[] b,int nStart,int nLen) ;1@C_5C
{ ';6X!KY+]
int n = -1; q[P~L`h S
try{ -KiRj!v|
oSavedFile.write(b,nStart,nLen); +8f>^*:u
n = nLen; 2 5Q+1
} @V$I?iXV
catch(IOException e) &$F[/[Ds+
{ -D#5o,]3
e.printStackTrace (); @bT3'K-4
} dQ<(lzS~
g5}lLKT
]YsR E>
return n; T`?n,'!(
} @^!\d#/M
\!<"7=(J{4
b/nOdFO@
} wWTQ6~Y%d
y@A6$[%(E|
^X&)'H
/* &dRjqn^&X
**SiteInfoBean.java b66R}=P l
*/ [/OQyb4F<
package NetFox; ,]7XMU3
&2{]hRM
c|lU(Tf
public class SiteInfoBean { j&CZ=?K^c
q`^3ov^</
WYLX?x
private String sSiteURL; //Site's URL >)^NJ2Fd
private String sFilePath; //Saved File's Path <Y>3
private String sFileName; //Saved File's Name o8{<qn|
private int nSplitter; //Count of Splited Downloading File W`x)=y]Z
1~@|eWr|
)~}PgbZ^
public SiteInfoBean() +9zA^0
{//nSplitter的缺省值为5 ~KRnr0
//default value of nSplitter is 5 ~C|,b"
this("","","",5); E0YU[([G
} eu9w|g
@6b[GekZ<
Q>=-ext}q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *H"aOT^{
{ y9!:^kDI
sSiteURL= sURL; ;Iq5|rzDn
sFilePath = sPath; K_#UZA< Y
sFileName = sName; uNbIX:L,
this.nSplitter = nSpiltter; {y6C0A*
-!TcQzHUs
D0ruTS
} TsD;Kl1
A"4@L*QV
3ji:O T
public String getSSiteURL() + |C=ZU
{ .S_QQM}Q
return sSiteURL; U5<@<j(@
} o/1JO_41
RZh}:
(6R4 \8z2
public void setSSiteURL(String value) &@6 GI<
{ g$w6kz_[
sSiteURL = value; A(+:S"|@
} ;SY.WfVA7
e+@xsn3
QNArZ6UQ
public String getSFilePath() ,|pp67
{ t$ZkdF
return sFilePath; J3=BE2L
} *1bzg/T<
)GJP_*Ab
Qh-4vy=r
public void setSFilePath(String value) m7m \`;
{ cPuHLwwYf
sFilePath = value; e$wt&^W
} |<(t}}X
XLb0 9;
tjxvN 4l
public String getSFileName() C:GvP>
{ Qq3fZ=
return sFileName; `6F+Rrn
} w$>3pQ8d
jBpVxv
}OrYpZob
public void setSFileName(String value) /DO'IHC.o
{ UX_I6_&
sFileName = value; zfjw;sUX
} 3LW[H+k
>a=d;
>^3zU
public int getNSplitter() >nry0 ;z0,
{ +'XhC#:
return nSplitter; l^r' $;<m
} Mr*|9h
S$O,] @)
2EfflZL3
public void setNSplitter(int nCount) "HC)/)Mv@
{ c7qwNs*f
nSplitter = nCount; @~o`#$*|
} 3eKQ<$w
} }q'WC4.
GuO`jz F
wiE]z
/* yd>}wHt
**Utility.java ?/d!R]3
*/ wL2XNdo}<
package NetFox; l!IGc:
``9 GY
^,V[nfQR
public class Utility { Q4wc-s4RN
#T\
%&<W(|U1<
public Utility() o:UXPAj
{ `^##b6jH
te'*<HM
|4Ha?W
} s'L?;:)dyB
a+?~;.i~
//线程睡眠 'm O2t~n
public static void sleep(int nSecond) )(bxpW
{ j}RzXJ~t
try{ T~s}Nx#
Thread.sleep(nSecond); yVS\Q,:J9
} sKfXg`0
catch(Exception e) wFL3&*
{ cOku1g8
e.printStackTrace (); 70Ka!
} 3ATjsOL
} "s]y!BLk
>&Fa(o;*
//日志 NHiq^ojk
public static void log(String sMsg) m mw-a0
{ 6c<ezEJ
System.err.println(sMsg); Q6^x8
} 6fwY$K\X
T=\!2gt
~HDdO3
public static void log(int sMsg) Np)aS[9W
{ dWR1cvB(wY
System.err.println(sMsg); HomN/wKh
} >.LKct*5K
} l`gTU?<xd
]}LGbv"`A
xjq0D[
/* 2P5_zND
**TestMethod.java _e'Y3:
*/ {4rQ7J4Ux
package NetFox; jJ++h1 K
qtzRCA!9(Z
{L0;{
public class TestMethod { ^?"^Pmw
zk=\lp2
r4;Bu<PQN1
public TestMethod() !T'X 'Q
{ ///xx/weblogic60b2_win.exe nq;#_Rkr
try{ X~RH^VYv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); z\.1>/Z=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nyhMnp#<
SiteFileFetch fileFetch = new SiteFileFetch(bean); z $6JpG
fileFetch.start(); C6@t
} 'IQsve7cI
catch(Exception e){e.printStackTrace ();} xb$yu.c
.>]N+:O
OVswt
} dZ2`{@AYY
8$}OS-
Oif,|:
public static void main(String[] args) Vxh.<b6&'
{ [Ox(.
new TestMethod(); Y<LNQ]8\G
} h&'=F)5
} 1D{#rA.X
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