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)); "+6:vhP5
} W+C@(}pt
for(int i=0;i<nEndPos.length-1;i++) "V;5Lp b
{ feH|sz`e
nEndPos = nStartPos[i+1]; }Ra'`;D$
} 1k *gbXb
nEndPos[nEndPos.length-1] = nFileLength; Uz`K#Bz
} DFKumw>!
} CAhkv0?8
Gw5j6
_*SA_.0
//启动子线程 ymxYE#q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m.}Yn,
for(int i=0;i<nStartPos.length;i++) 5g{F-
{ :bhpYEUMx
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^K#PcPF-j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), t'@qb~sf
nStartPos,nEndPos,i); $YX\&%N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1UHStR
fileSplitterFetch.start(); 61W ms@D%
} 4t0B_o"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Sf2pU!5n^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >(} I7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mrzrQ@sN
nEndPos = " + nFileLength); v~2$9x!9
// fileSplitterFetch[nPos.length-1].start(); RiY9[ec2
AI|8E8h+D
o6PDCaT7
//等待子线程结束 Tjfg[Z/x
//int count = 0; LyRU2A
//是否结束while循环 FM)Es&p&
boolean breakWhile = false; YtzB/q8I
ptrQ~m-
TfYXF`d
while(!bStop) K9#=@}!3L
{ ]+SVQ|v0
write_nPos(); /=5YHq>
Utility.sleep(500); I'_u4
breakWhile = true; us2X:X)
'n9<z)/,!
a19yw]hF5
for(int i=0;i<nStartPos.length;i++) Y 7a<3>
{ SOq{`~,4B
if(!fileSplitterFetch.bDownOver) ~qG`~/7
{ uK:?6>H
breakWhile = false; =lzRx%tm
break; f:_\S
} TfD]`v`]
} B}%B4&Ij
if(breakWhile) =Mb1)^m
break; iG\]
dA`.
D]H@Sx
//count++; ^=H. .pr
//if(count>4) SxHj3,`#C
// siteStop(); GvL)SVv?
} v[r5!,F
1 h.=c
)}-,4Iu%
System.err.println("文件下载结束！"); &B</^:
} S}/?Lm}
catch(Exception e){e.printStackTrace ();} ?Mb'l4
} *nv%~t
L"w% ew
L8&$o2+07r
//获得文件长度 '.sS"QdN
public long getFileSize() I.f)rMl+h
{ +J^-B}v
int nFileLength = -1; z$VA]tI(
try{ *?zyF@K{%
URL url = new URL(siteInfoBean.getSSiteURL()); 5Iv3B|u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2{v$GFc/
httpConnection.setRequestProperty("User-Agent","NetFox"); TTS.wBpR,
%>dCAj"
u7_IO
int responseCode=httpConnection.getResponseCode(); 9t.u9C=!F
if(responseCode>=400) v&hQ;v
{ YceX)
processErrorCode(responseCode); :N\j@yJK
return -2; //-2 represent access is error U#I8Rd I,
} p7UdZOi2
`aj;FrF
7X h'VOljB
String sHeader; Op&i6V}<s
h&$7^P
td:GZ %
for(int i=1;;i++) }tvLe3O
{ l\PDou@5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j4ARGkK5B
//Utility.log(in.readLine()); MeXzWLH
sHeader=httpConnection.getHeaderFieldKey(i); bbDl?m&bq
if(sHeader!=null) GOT@
{ (v11;kdJB
if(sHeader.equals("Content-Length")) WOW:$.VO^
{ uM!$`JN
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 39xAh*}G]
break; U*G8}W
} BO#XQ,
} ~i)m(65:
else {*gO1TZt9
break; LciSQ R!
} 9] i$`y
} w4m-DR5
catch(IOException e){e.printStackTrace ();} AY{-Hf&
catch(Exception e){e.printStackTrace ();} 9~bl
PGaB U3
zYCrfr
Utility.log(nFileLength); :[;]6;
F/MzrK\':m
&+@~;p5F
return nFileLength; f`zH#{u
} Q.3oDq
MIblx
^6tcB* #A
//保存下载信息（文件指针位置） l98.Hb7
private void write_nPos() huMNt6P[
{ fOE8{O^W
try{ L/2{}l>D
output = new DataOutputStream(new FileOutputStream(tmpFile)); So&an !
output.writeInt(nStartPos.length); zh5$$*\
for(int i=0;i<nStartPos.length;i++) J^}w,r*=
{ o5!"dxR
// output.writeLong(nPos); Q_ zGs6
output.writeLong(fileSplitterFetch.nStartPos); *h+@a
output.writeLong(fileSplitterFetch.nEndPos); Pm2T!0
} .T*K4m{b0
output.close(); X6+2~'*t
} I%.96V
catch(IOException e){e.printStackTrace ();} ~hubh!d=
catch(Exception e){e.printStackTrace ();} OQ[E-%v1 R
} t7A '
KC+C?]~M
qTbY'V5A
//读取保存的下载信息（文件指针位置） 1ga-8&!
private void read_nPos() v35wlt^}
{ 3kAmRU
try{ yv.Y-c=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m!{}Y]FZn
int nCount = input.readInt(); I)wjTTM5
nStartPos = new long[nCount]; 5|&:l8=
nEndPos = new long[nCount]; s0,\[rM
for(int i=0;i<nStartPos.length;i++) *?;<buJb?
{ OYcf+p"<\
nStartPos = input.readLong(); JfJUOaL
nEndPos = input.readLong(); +-b:XeHSZ
} ?y.q<F)
input.close(); h8IjTd]z{$
} 6XVr-ef
catch(IOException e){e.printStackTrace ();} [iJU{W
catch(Exception e){e.printStackTrace ();} Hwr# NKz-
} kbqG)
)_*<uSl
d2b L_
private void processErrorCode(int nErrorCode) +UzFHiGy#
{ ]SNA2?q
System.err.println("Error Code : " + nErrorCode); ZTCzD8
} Yzr RnVr
PUMh#^g}
5k0r{^#M
//停止文件下载 l?>sLKo9
public void siteStop() /u9Md3q*'
{ v3b[08 F
bStop = true; 6pkZ8Vp:
for(int i=0;i<nStartPos.length;i++) ,2Y PD4
fileSplitterFetch.splitterStop(); b;wf7~a*
OBGA~E;%
3t
} GCN(
} >Ab>"!/'K
//负责部分文件的抓取 Yg 8AMi
**FileSplitterFetch.java 2ckAJcpEb/
*/ B{fPj9Y0
package NetFox; J(BtGGU'
T[mo PD5
!PN;XZ~{
import java.io.*; nC^|83
import java.net.*; Z]$RO
[emUyF
X~/hv_@
public class FileSplitterFetch extends Thread { EJ$-
n^8LF9r
#;Yn8'a~
String sURL; //File URL DNsDEU
long nStartPos; //File Snippet Start Position ]~my<3j}or
long nEndPos; //File Snippet End Position gu+c7qe
int nThreadID; //Thread's ID =NyN.^bwT
boolean bDownOver = false; //Downing is over mQRQ2SN6
boolean bStop = false; //Stop identical C-@
FileAccessI fileAccessI = null; //File Access interface R[eQ}7;+
Evd>s
8 *@knkJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s1,kTde
{ zWiMl.[
this.sURL = sURL; *9"L?S(X#
this.nStartPos = nStart; i ! wzID
this.nEndPos = nEnd; =^.f)
nThreadID = id; tw.2h'D
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <ex,@{n4
} 1:-^*
K`!q1g`
!^Mk5E(
public void run() SK2nxZOH
{ TNs0^h)
while(nStartPos < nEndPos && !bStop) xPa>-N=*
{ JpVV0x/Q/_
2ql7*g?Uq@
B_FfXFQm<
try{ f =H,BQ
URL url = new URL(sURL); z7+y{-{Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ([loWr}QR
httpConnection.setRequestProperty("User-Agent","NetFox"); !!Tk'=t9"3
String sProperty = "bytes="+nStartPos+"-"; 0 S3~IeJ
httpConnection.setRequestProperty("RANGE",sProperty); gi::?ET/.
Utility.log(sProperty); \>0F{-cR$
pdnkHR$
Xg*IOhF6x
InputStream input = httpConnection.getInputStream(); 4l! ^"=rh
//logResponseHead(httpConnection); 3c5=>'^F
ZyE2=w7n
8Z;wF
byte[] b = new byte[1024]; *G"vV>OSV
int nRead; tAD{{GW9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {7^7)^@
{ yteJHaq
nStartPos += fileAccessI.write(b,0,nRead); 'jp nQcwxx
//if(nThreadID == 1) w$J0/eX{A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H-%)r&"vn
} MF>1u%
?>lvV+3^`
u@SE)qg
Utility.log("Thread " + nThreadID + " is over!"); Y21,!$4gb
bDownOver = true; sY?pp '}a
//nPos = fileAccessI.write (b,0,nRead); owA3>E5t&
} 846j<fE
catch(Exception e){e.printStackTrace ();} cnAwoTt4
} 'U<-w$!f+^
} mk JS_6
&&e{9{R
O@U[S.IK
//打印回应的头信息 ?9qA"5
public void logResponseHead(HttpURLConnection con) J~z;sTR
{ EUdu"'=4a
for(int i=1;;i++) 7+aTrE{
{ "rz|sbj
String header=con.getHeaderFieldKey(i); y}jX/Ln
if(header!=null) Ba/Z<1)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H27J kZ&
Utility.log(header+" : "+con.getHeaderField(header)); zuOx@T^
else ?'H);ou-p
break; /kGRN@
} ^n5[pF}Gw
} M70Xdn
;$W/le"Xr
+O23@G?x
public void splitterStop() O~F/pJN`
{ T2# W=P
bStop = true; gvYib`#
} {t: ZMUV
C)> ])'S
gBRhO^Sz
} )f4D2c&VE
{N+N4*
_H|c_
/* zECdj'/
**FileAccess.java =p>"PqJ/7n
*//文件访问(定位，写) P/._ tQu6
package NetFox; y|!%C-P
import java.io.*; Xui${UYN
gkS#=bv9e@
c8mcJAc
public class FileAccessI implements Serializable{ c_xtwdkL9
=?UCtYN,P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~~]/<d
RandomAccessFile oSavedFile; WAiEINQ^)
long nPos; }x4,a6^
UM%[UyYQ
2A@9jl s
public FileAccessI() throws IOException dwks"5l
{ tYyva
this("",0); >jAr9Blz]
} rAD5n,M]
vrXmzq
+]Of f^s
public FileAccessI(String sName,long nPos) throws IOException POTW+Zq]
{ .['@:}$1
oSavedFile = new RandomAccessFile(sName,"rw"); }gL9G
this.nPos = nPos; qOz,iR?}
oSavedFile.seek(nPos); RsU=fe,
} ")7,ZN;
QOIi/flK
l(9$s4R
public synchronized int write(byte[] b,int nStart,int nLen) u4B,|_MK
{ U7J0&
int n = -1; }(O/y-
try{ { 'Hi_b3
oSavedFile.write(b,nStart,nLen); dz.]5R
n = nLen; cs`/^2Vf"#
} .z+?b8Q\
catch(IOException e) R3F>"(P@tS
{ %JDG aG'
e.printStackTrace (); (utm+*V,
} :7p0JGd
~c[}%Ir>
Pgg6(O9}B^
return n; AY:3o3M
} K|];fd U
6cSMKbgZJ
>]Hz-2b
} H[V^wyi'z
/ee:GjUkB
S5d:?^PGg
/* ^4]#Ri=U
**SiteInfoBean.java sj2v*tFb
*/ ([UuO}m-
package NetFox; +Uq9C-Iu
B{a:cz>0<
MQE=8\
public class SiteInfoBean { JU:!lyd
dra'1E
k);z}`7
private String sSiteURL; //Site's URL y&9S+
private String sFilePath; //Saved File's Path Ri4_zb
private String sFileName; //Saved File's Name Gk,{{:M:5
private int nSplitter; //Count of Splited Downloading File rB?u.jn0T
Vj4 if@Z
xPb;_~
public SiteInfoBean() #`:s:bwM:
{//nSplitter的缺省值为5 f2_LfbvH
//default value of nSplitter is 5 +-'qI_xo
this("","","",5); !$AVlMnJ
} 7GfgW02
"%urT/Fv&
lf0/0KH
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P~_CDh.N
{ PTA;a0A
sSiteURL= sURL; swG^L$r`
sFilePath = sPath; >NB}Bc
sFileName = sName; a\vf{2
this.nSplitter = nSpiltter; <,Sy:>:"
t2p/NIn
r4JXbh6Tt
} g}Hk4+
/`\-.S9
0-0 )E&2
public String getSSiteURL() 7EY~5U/4
{ A/{pG#if]3
return sSiteURL; %%c0UaV
} @5 kKMz
!/< 5.9!9r
,p1 (0i
public void setSSiteURL(String value) =t@m:
{ FvG9PPd
sSiteURL = value; ?*}76u
} Mn>dI@/gM
Qu!\Cx@
jm RYL("
public String getSFilePath() R|V<2
{ ol!o8M%Q
return sFilePath; kSU5 }
} 68FxM#xR
bw%1*;n)
+Jt"JJ>%k
public void setSFilePath(String value) =e$ #m;
{ Hxb{bF
sFilePath = value; `Kym{og
} UgJlXB|a%2
]~WP;o
&M>S$+I n
public String getSFileName() hp-<8Mf
{ CSr{MF`]e
return sFileName; YL){o$-N"J
} 4Xz6JJ1U[H
3 %DA{
qu[w_1%S
public void setSFileName(String value) ,;/4E
{ W3<O+S&
sFileName = value; u:HKmP;
} rFx2S
ljiq+tT
!ox&`
public int getNSplitter() J3:P/n&
{ /;OJ=x3i
return nSplitter; 4T^M@+&|
} m9L+|r
jb7=1OPD_
g!~j Wn?A
public void setNSplitter(int nCount) //J:p,AF
{ rA1 gH6D
nSplitter = nCount; A:D\!5=
} $35Oyd3s<
} @%#(Hse
G x,D'H'
]6:5<NW
/* 8U;!1!+ 7)
**Utility.java Ev^Xs6 }"
*/ ZzKn,+
package NetFox; `Mjm/9+18
"Q/3]hc.
y:,{U*49
public class Utility { qHKZ5w
_p_F v>>:
92SB'T>
public Utility() x _2]G'
{ Q1jyetk~I
ITsJjcYw
&a|oJ'clz
} yjSN;3t71
@?1%*/
//线程睡眠 ]!A;-m
public static void sleep(int nSecond) *,Re&N8
{ =?f}h{8x>
try{ H!Od.$ZIX
Thread.sleep(nSecond); cYp}$
} $(NfHIX
catch(Exception e) r[,KE.^6~#
{ kl={L{r
e.printStackTrace (); r]E$uq bR
} q@\_q!
} JJ+<?CeHD
Y{O&-5H^|
//日志 g@U#Y#b@"
public static void log(String sMsg) +p[~hM6?
{ T2->
System.err.println(sMsg); =3T?U_u@
} _4W#6!
:D,YR(])
<VBw1|)$@
public static void log(int sMsg) oby*.61?5l
{ |`okIqp
System.err.println(sMsg); \8$`:3,@
} %*gO<U4L]
} #<~f~{x
y{"E)YY
[x)e6p)
/* dL\8^L
**TestMethod.java {L=[1
*/ J)G3Kq5>:b
package NetFox; 9s!/yiP5
"5YdmBy
O`u!P\
public class TestMethod { \fhT#/0N
C1/jA>XW
xHGoCFB
public TestMethod() d"78:+
{ ///xx/weblogic60b2_win.exe gfYB|VyWo
try{ Qx6/QaS?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); v<SEGv-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); KRtu@;?
SiteFileFetch fileFetch = new SiteFileFetch(bean); e?YbG.(E9
fileFetch.start(); 4yA`);r62
} A!D:Kc3
catch(Exception e){e.printStackTrace ();} ]Rye AJ3
Z C93C7lJ
j+9 S
} @5wg'mM
V\"5<>+O
NM@An2
public static void main(String[] args) sV<4^n7
{ Q7r,5w&cm
new TestMethod(); =5`@:!t7
} `/zt&=`VB
} 4I*Mc%dD
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