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)); LN^8U
} f*~fslY,o
for(int i=0;i<nEndPos.length-1;i++) A~>=l=
{ FHC7\#p/9Z
nEndPos = nStartPos[i+1]; DIAP2LR ?
} bW|y -GM
nEndPos[nEndPos.length-1] = nFileLength; &$Lm95
} 8(;i~f:bCW
} iE`aGoA
jg8P4s
dp70sA!JF
//启动子线程 D=vq<X'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~] 2R+
for(int i=0;i<nStartPos.length;i++) :\OvVS/
{ "!?bC#d#(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BxU1Q&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A{%;Hd`0/
nStartPos,nEndPos,i); 4Ccb!?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e8 aV qq[
fileSplitterFetch.start(); Y ckbc6F
} kDh(~nfj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bl<7[J.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O2dgdtm
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", am3E7u/
nEndPos = " + nFileLength); gi>_>zStv
// fileSplitterFetch[nPos.length-1].start(); =;=V4nKN
y~jIAp
Gf\_WNrSE+
//等待子线程结束 uyj*v]AE'
//int count = 0; jYz3(mM'J
//是否结束while循环 .*blM1+6i/
boolean breakWhile = false; '=.Uz3D'0
E;H(jVZ
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while(!bStop) f:5/y^M&
{ X~3P?O]kFv
write_nPos(); 4/WCs$
Utility.sleep(500); /nFw
breakWhile = true; e~;)-Z
hp4(f W
[i1D~rCcn
for(int i=0;i<nStartPos.length;i++) DG?\6Zh
{ )du{ZWr
if(!fileSplitterFetch.bDownOver) qL.Y_,[[
{ h_yR$H&tX
breakWhile = false; z{L;)U B^
break; _|:bac8pL
} F@bCm+z-
} \#,#_
if(breakWhile) R}9jgB
break; 5q`)jd!*)
7`@?3?
[#'_@zZz
//count++; z.HNb$;
//if(count>4) B1#>$"_0}=
// siteStop(); F)kLlsp
} NOp=/
4(GgaQFO?
r~_ /Jj
System.err.println("文件下载结束！"); `f+g A
} 3#9r4;&
catch(Exception e){e.printStackTrace ();} %P,^}h7
} G0Tc}_o<Y
c.A/{a
E(+wl
//获得文件长度 W<]Oo]
public long getFileSize() P\6T4s
{ ~<[5uZIo
int nFileLength = -1; N/{Yi _n
try{ [mzF)/[_2
URL url = new URL(siteInfoBean.getSSiteURL()); :42;c:85
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GiO#1gA
httpConnection.setRequestProperty("User-Agent","NetFox"); gJ8 c]2c
x&oBO{LNK,
fA0=Y,pzv
int responseCode=httpConnection.getResponseCode(); xYVjUb(,X
if(responseCode>=400) 7+hF;
{ +Z~!n
processErrorCode(responseCode); }\L!;6oy
return -2; //-2 represent access is error k+r9h'd
} SM#S/|.]
(p.3'j(
?7nr\g"g(
String sHeader; G!VF*yW8
_X2EBpZp
6^IqSNn-
for(int i=1;;i++) *xo;pe)9
{ H~dHVQtJZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cI%"Ynq"3
//Utility.log(in.readLine()); L}jF#*Q%
sHeader=httpConnection.getHeaderFieldKey(i); N>pmhskN?
if(sHeader!=null) 1^f.5@tV
{ ?X#/1X%u:
if(sHeader.equals("Content-Length")) ~'NpM#A
{ o%WjJ~!zL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b~r{J5x@
break; T<f\*1~^
} >'}=.3\
} w*u{;v#
else B&i0j5L
break; O%JsUKV
} =0PRAc
} )o9Q5Lq
catch(IOException e){e.printStackTrace ();} I& M36f
catch(Exception e){e.printStackTrace ();} K4k~r!&OU
z{@R.'BD
h^A3 0f_x
Utility.log(nFileLength); /j' B\,
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1O7]3&L@
return nFileLength; rXY;m-
} cZgMA8 F
)W`SC mr]
}{5mH:
//保存下载信息（文件指针位置） UK6xkra?#
private void write_nPos() k6O.H
{ p"[O#*p
try{ Gg9VS&VI
output = new DataOutputStream(new FileOutputStream(tmpFile)); yOWOU`y?
output.writeInt(nStartPos.length); /Fe:h>6
for(int i=0;i<nStartPos.length;i++) ^Ue0mC7m
{ @n7t?9Bx
// output.writeLong(nPos); (S k#x
output.writeLong(fileSplitterFetch.nStartPos); U!c]_q
output.writeLong(fileSplitterFetch.nEndPos); G[3k
} -=$% {
output.close(); ieo|%N{'
} dh^+l;!L
catch(IOException e){e.printStackTrace ();} [IX*sr
catch(Exception e){e.printStackTrace ();} v<;: 0
} gEv->pc
Mlv<r=E
*O@sh
//读取保存的下载信息（文件指针位置） >[ug zJ
private void read_nPos() @iU%`=ziz
{ F#(.v7Za
try{ {ITv&5?>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )n7|?@5U
int nCount = input.readInt(); 'h-3V8m^e
nStartPos = new long[nCount]; ^ <qrM
nEndPos = new long[nCount]; vd}*_d
for(int i=0;i<nStartPos.length;i++) 2Co@+I[,4&
{ dG&2,n'f
nStartPos = input.readLong(); fO].e"}
nEndPos = input.readLong(); [}>#YPZ
} J &!B|TS
input.close(); k$C"xg2
} e:N7BZl'c9
catch(IOException e){e.printStackTrace ();} T yU&QXb
catch(Exception e){e.printStackTrace ();} Ko#4z%Yq
} 9Z&?R++?
KNy`Lj)VPY
d,W/M(S
private void processErrorCode(int nErrorCode) P7z:3o.
{ >DL/..
System.err.println("Error Code : " + nErrorCode); L 5+J ^
} (nLKQV 1
,Ij=b
< CDA"
//停止文件下载 D9~}5
public void siteStop() 1e/L\Y=m
{ 2G?$X?
bStop = true; huz86CO
for(int i=0;i<nStartPos.length;i++) `h?LVD'l
fileSplitterFetch.splitterStop(); @0$}?2
t\8&*(&3F
Z| We9%
} KxY$PgcC
} 8Jr1_a
//负责部分文件的抓取 R*087X7 N|
**FileSplitterFetch.java ``!GI'^
*/ AM'gnP>
package NetFox; jo)6 %w]
be7L="vZw
> @+#
import java.io.*; 8W;2oQN7
import java.net.*; F"'n4|q4n
ibXe"X/_
ryg4hHspl
public class FileSplitterFetch extends Thread { #4><r.v3
qIh #~
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String sURL; //File URL "}@i+oS
long nStartPos; //File Snippet Start Position nd:E9:
long nEndPos; //File Snippet End Position MAnp{
int nThreadID; //Thread's ID G+VD8]!K1
boolean bDownOver = false; //Downing is over <W*xshn
boolean bStop = false; //Stop identical :6Pnie
FileAccessI fileAccessI = null; //File Access interface `}gdN};
|g<*Rk0
! RPb|1Y}+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Iq^if>
{ b#/i.!:a
this.sURL = sURL; DL{R|3{N
this.nStartPos = nStart; h*3{6X#(/
this.nEndPos = nEnd; 1CkdpYjsj
nThreadID = id; "~/9F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 K'aWCscM
} +{$QAjW(/
cwe1^SJ6y
K"\MU
public void run() PK4`5uT
{ GX?*1
while(nStartPos < nEndPos && !bStop) R^%e1KO]
{ 7J|&U2}c
}"_j0ax
'e@=^FC
try{ LnFWA0y
URL url = new URL(sURL); MR$>!Nlp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BAV>o|-K
httpConnection.setRequestProperty("User-Agent","NetFox"); R?pRxY
String sProperty = "bytes="+nStartPos+"-"; gsPl _
httpConnection.setRequestProperty("RANGE",sProperty); +7U
Utility.log(sProperty); eEl.. y
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S&(^<gwl
InputStream input = httpConnection.getInputStream(); X}cZxlqc
//logResponseHead(httpConnection); G[h(xp?,l
fP[& a9l
ECcZz.
byte[] b = new byte[1024]; <G~>~L.E
int nRead; |0.Xl+7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @I-Lv5
{ 4woO;Gm
nStartPos += fileAccessI.write(b,0,nRead); 3s*(uS(
//if(nThreadID == 1) 0Fw6Dq<8-!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o''wCr%
} BqH]-'1G
nfdq y)
}BJX/, H,
Utility.log("Thread " + nThreadID + " is over!"); -*a?<ES`
bDownOver = true; L]d-33.c!H
//nPos = fileAccessI.write (b,0,nRead); <>Y?vC
} +4qU>
catch(Exception e){e.printStackTrace ();} DmqSQA
} p fT60W[m
} '+Xlw
WYrI|^[>
=ll=)"O
//打印回应的头信息 Vj?DA5W`'
public void logResponseHead(HttpURLConnection con) v~|?3/{Q
{ }{[mrG
for(int i=1;;i++) IMGP'g
{ 'CR)`G_'[
String header=con.getHeaderFieldKey(i); +q<B.XxkA
if(header!=null) MJ{%4S{K,p
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $s5a G)?7
Utility.log(header+" : "+con.getHeaderField(header)); >[10H8~bI/
else M@Q3M(z
break; As&vFt P
} s{bdl[7
} 8,"yNq
sTRJ:fR
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public void splitterStop() ;gg\;i}^
{ >rsqH+oL
bStop = true; e8=YGx^o`
} gB'fFkd
a2 +~;{?g
I@#;nyAj"
} tWeFEVg
l^MzN
a>O9pX
/* 8flOq"uK^
**FileAccess.java M<PIeKIEB
*//文件访问(定位，写) ?:{sH#ua
package NetFox; RoGwK*j0+
import java.io.*; mLV[uhq
U?a6D:~G
*Lqg=9kzr
public class FileAccessI implements Serializable{ =3ioQZ^Vz
#>=j79~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q#w8wH"
RandomAccessFile oSavedFile; Fs_]RfG
long nPos; U6E\AvbRn
Ian[LbCWB
jHXwOJq %
public FileAccessI() throws IOException v3d&*I
{ %p^.|Me7
this("",0); dovZ#D@Q
} W14F
)a@k]#)Skm
P 3MhU;
public FileAccessI(String sName,long nPos) throws IOException ML;*e"$
{ :cu#V
oSavedFile = new RandomAccessFile(sName,"rw"); jHN +5=l
this.nPos = nPos; !`1'2BC
oSavedFile.seek(nPos); r(d':LV
} tCxF~L@
No]~jnqDM
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public synchronized int write(byte[] b,int nStart,int nLen) jls-@Wl
{ akw,P$i
int n = -1; 1f",}qe;
try{ _@S`5;4x
oSavedFile.write(b,nStart,nLen); `qJw|u>YpJ
n = nLen; 3(C\.oRc
} Zo1,1O
catch(IOException e) .EM`.
{ zOg7raIa
e.printStackTrace (); uqz]J$
} O G<,- 7
{uzf"%VtP
>pUtwIP
return n; @gY)8xMbA
} cwiX8e"3
cGjPxG;
;M"9$M'
} g}@OUG"D
: ]C~gc
3R+|5Uq8~
/* boDt`2=
**SiteInfoBean.java J:V?EE,\-
*/ <b,~:9*?
package NetFox; d!eYqM7-G
p/+a=Yo
w@,zFV
public class SiteInfoBean { j?'GZ d"B
`OSN\"\ad
N7e"@Ic
private String sSiteURL; //Site's URL wI(M^8F_Mf
private String sFilePath; //Saved File's Path a+n0|CvF
private String sFileName; //Saved File's Name c38D}k^):
private int nSplitter; //Count of Splited Downloading File UX7t`l2R
#U14-^7
82l~G;.n3
public SiteInfoBean() ;^Dpl'v%\
{//nSplitter的缺省值为5 EFz&N\2
//default value of nSplitter is 5 4:FK;~wM&x
this("","","",5); zCk^B/j sM
} !r<pmr3f@7
s0vDHkf8
.SWlp2!M5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <7~'; K
{ -fDnA4;
sSiteURL= sURL; a|X a3E
sFilePath = sPath; Hj}K{20
sFileName = sName; @{25xTt
this.nSplitter = nSpiltter; 6Yln,rC
|p,P46I
W)bLSL]`E
} T:~vk.Or
'tH_p
q#%xro>m
public String getSSiteURL() P5UL4uyl
{ J\b^)
return sSiteURL; +{oG|r3L
} 5?x>9Ca
x<ZJb
VXwU?_4J.
public void setSSiteURL(String value) K|[*t~59
{ lNYt`xp
sSiteURL = value; X9V*UXTc
} 9w7n1k.
1ukTA@Rj&
dl.p\t(1
public String getSFilePath() fumm<:<CLO
{ Jcd-
return sFilePath; R[D{|K@"
} ``hf=`We
1G^`-ri6
YIG~MP
public void setSFilePath(String value) I=`U7Bis"
{ 3`DQo%<
sFilePath = value; _uy44;zq
} vg32y /l]S
iP7(tnlW$
r7%I n^k
public String getSFileName() VY7[)
{ AP 2_MV4W
return sFileName; 3YR!Mq$|~
} (c=6yV@
];[}:f
Nk? ^1n$
public void setSFileName(String value) ?]_$Dcmx
{ |\pj;XU
sFileName = value; KQ!8ks]
} l<58A7
,~N/- 5
61C7.EZZ;
public int getNSplitter() \/r}]Vz
{ H)kwQRfu
return nSplitter; 7rc0yB
} >* f-Wde
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;"5&b!=t
public void setNSplitter(int nCount) ;PF<y9M
{ -A^_{4X
nSplitter = nCount; !C':
} [Kg+^N%+
} /L g)i\R;
P9^Xm6QO
u5`u>.!
/* y4?0j:
**Utility.java r= `Jn6@
*/ l`lk-nb
package NetFox; ]vUwG--*
MS~(D.@ZS
-V77C^()8d
public class Utility { ,aZ[R27rpL
C_}]`[
HmGWht6R
public Utility() DN>[\hg
{ ?=sDM& '
:D5Rlfj
w3ResQ
} hn GZ=
zj{pJOM06
//线程睡眠 <44G]eb
public static void sleep(int nSecond) AofKw
{ IVY]EkEG~
try{ r(TIw%L$
Thread.sleep(nSecond); UcHJR"M~c
} Q->sV$^=T
catch(Exception e) \;Biq`
{ q"lSZ; 'E
e.printStackTrace (); kiaw4_
} `Y$4 H,8L
} D%pF;XY
j_?FmX _
//日志 "%w u2%i
public static void log(String sMsg) tXs\R(?T
{ -`h)$&,
System.err.println(sMsg); zR:L!S
} =&]g "a'
xJ]\+ 50
(y~TL*B
public static void log(int sMsg) 4xje$/_d
{ )Nw8O{\
System.err.println(sMsg); i-_mTY&M
} N=}A Z{$
} Cl7xt}I
#=A)XlZMd
XNkn|q2
/* 6A-|[(NS
**TestMethod.java +I|vzz`ZVr
*/ ?N9uu4
package NetFox; 3F2w-+L
!_)[/q"
@I?=<Riu
public class TestMethod { 5U$0F$BBp
+ye3HGD
0aB;p7~&
public TestMethod() E ~<JC"]
{ ///xx/weblogic60b2_win.exe 9rf)gU3{+L
try{ `d}2O%P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W/h[A3 `3N
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); BRiE&GzrF
SiteFileFetch fileFetch = new SiteFileFetch(bean); s.C_Zf~3
fileFetch.start(); XW]tnrs
} kt:! 7
catch(Exception e){e.printStackTrace ();} 0\P1; ak%
tGa8W
4H&+dRI"
} yY q,*<G
U>N1Od4vTO
o>pJPV
public static void main(String[] args) ,k3FRes3
{ 4,DeHJjAlE
new TestMethod(); }pkzH'$HJ
} oCz/HQoBk
} Sdryol<
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