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)); m^dKww
} -ec~~95
for(int i=0;i<nEndPos.length-1;i++) bP%0T++vo
{ B;A^5~b
nEndPos = nStartPos[i+1]; ][8ZeM9&p
} =;.#Bds
nEndPos[nEndPos.length-1] = nFileLength; eW$G1h:
} 9QaEUy*,
} ,Mf@I5?
{K-]nh/
9Ny{2m=Ye
//启动子线程 [4:_6vd7X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; V#;6<H"
for(int i=0;i<nStartPos.length;i++) \S(:O8_"68
{ HFD5*Z~M
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cyq]-B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $ig%YB
nStartPos,nEndPos,i); Fx']kn9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )--v>*,V
fileSplitterFetch.start(); 8fzmCRFH
} >Zk$q~'+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Km2ppGLNn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pEIc?i*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rf"%D<bb
nEndPos = " + nFileLength); unqX<6hu
// fileSplitterFetch[nPos.length-1].start(); f $MVgX
%\?2W8Qv_J
eiB5 8b3
//等待子线程结束 ,?;q$Xoi
//int count = 0; riqvv1Nce
//是否结束while循环 7_ g}t!b`
boolean breakWhile = false; 8=x{>&Jr&#
hv 18V>8
yyJ4r}TE
while(!bStop) _K{hq<g
{ ^g`1SU`
write_nPos(); SGn:f>N
Utility.sleep(500); #z{9:o7[-
breakWhile = true; {.tUn`j6V
1_uq46
hPt(7E2ke~
for(int i=0;i<nStartPos.length;i++) ]qCAog
{ +D|y))fE
if(!fileSplitterFetch.bDownOver) y?W8FL
{ d_BO&k<+I
breakWhile = false; rt] @Z`w
break; cF_hU"
} mT\!LpX
} V2kNJwwk
if(breakWhile) E<;C@B
break; ~JY<DW7
zm rQ7(y
IH?.s k
//count++; F,^Q'$!
//if(count>4) \k;)m-0bj{
// siteStop(); ou6|;*>d
} l+S08IZ
^+cf
)`]w\s #
System.err.println("文件下载结束！"); 6R% I)
} X_XeI!,b
catch(Exception e){e.printStackTrace ();} 'M2Jw8i
} UX=JWb_uGm
RWf4Wh?d
('!90
//获得文件长度 #LEK?]y
public long getFileSize() +hg|!SS@5
{ c,;-[sn
int nFileLength = -1; z-nhL=
try{ HErTFY+vC
URL url = new URL(siteInfoBean.getSSiteURL()); 2bU3*m^M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); weC$\st:D
httpConnection.setRequestProperty("User-Agent","NetFox"); SLRQ3<0W_
{zhN>n_
i[)H!%RV*
int responseCode=httpConnection.getResponseCode(); Dt\F]\6sd
if(responseCode>=400) }ex2tkz
{ Jla ;^X
processErrorCode(responseCode); |)QE+|?P
return -2; //-2 represent access is error Kr`Cr5v
} RP&H9>
p%5RE%u
3B95t-
String sHeader; *b9=&:pU(
!u)veh3x
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for(int i=1;;i++) zZDa71>
{ <T JUKznO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \M1-
//Utility.log(in.readLine()); 0}jB/Z_T
sHeader=httpConnection.getHeaderFieldKey(i); DWZ!B7Ts
if(sHeader!=null) 1QXv}36#3n
{ <e|I?zI9-
if(sHeader.equals("Content-Length")) hb7H- Z2
{ 4)ez0[i$X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zuR!,-W
break; S{aK\>>H
} MDa 4U@Q
} dN J2pfvv
else h{I)^8,M
break; BKe~y
} &^^zm9{
} *?%DdVrO@
catch(IOException e){e.printStackTrace ();} #WlIH7J8Tc
catch(Exception e){e.printStackTrace ();} I:[^><?E
)xIk#>)
jD9^DzFx
Utility.log(nFileLength); gy/z;fB
sF}T9Ue
_M= \s>;G
return nFileLength; dX-Xzg
} UOy9N
'+^HeM^;
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//保存下载信息（文件指针位置） _] veTAV
private void write_nPos() U=MFNp+
{ Z?Y14L~%
try{ Hzh?w!Ow
output = new DataOutputStream(new FileOutputStream(tmpFile)); wYK-YY:Q3
output.writeInt(nStartPos.length); !8M]n
for(int i=0;i<nStartPos.length;i++) smW 7zGE
{ V9f$zjpw
// output.writeLong(nPos); .4pWyqU)!
output.writeLong(fileSplitterFetch.nStartPos); |T0jq
output.writeLong(fileSplitterFetch.nEndPos); Q1? !,a
} Nw'i;}0v7r
output.close(); e*.l6H/B
} X*6bsYbK-
catch(IOException e){e.printStackTrace ();} GV'Y'
catch(Exception e){e.printStackTrace ();} vK z/-9im
} mnswGvY
+G*2f V>
}stc]L{79
//读取保存的下载信息（文件指针位置） tWy0% -
private void read_nPos() -v#0.3zm
{ 7(AB5.O
try{ SbI %|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8?AFvua}r
int nCount = input.readInt(); |u{NM1,
nStartPos = new long[nCount]; :it52*3=
nEndPos = new long[nCount]; ]P;Ng=a
for(int i=0;i<nStartPos.length;i++) 1*<m,.$
{ jh\L)a*
nStartPos = input.readLong(); XOK.E&eilj
nEndPos = input.readLong(); Q[J%
} Lgl%fO/<t
input.close(); e>\[OwF-x
} uuW._$.A>
catch(IOException e){e.printStackTrace ();} ," ~ew ,
catch(Exception e){e.printStackTrace ();} c.y8x
} j4>1a
Y S )Q#fP
"pGSz%i-
private void processErrorCode(int nErrorCode) B*#lkMr
{ t=\y|Idc
System.err.println("Error Code : " + nErrorCode); oZTKG'
} 45fk+#
zX{K\yp
57*`y'CW
//停止文件下载 X}C}
public void siteStop() ^Rriu $\
{ H7!j5^
bStop = true; A]^RV{P
for(int i=0;i<nStartPos.length;i++) z)N8#Y~vn
fileSplitterFetch.splitterStop(); }cuU5WQ?%
[;yEG$)K
bC{1LY0
} rkOLTi[$
} 1,q&A RTS
//负责部分文件的抓取 jA9&hbQuL
**FileSplitterFetch.java uBp"YX9rx
*/ ea!_/Y
package NetFox; Ao>] ~r0
i|A0G%m]$
9D,`9L5-=
import java.io.*; D/wX
import java.net.*; 2Ur9*#~kGp
DY| s|:d
= rDoXm
public class FileSplitterFetch extends Thread { co^kP##Y
H]2cw{2
jinDKJ,n;
String sURL; //File URL ha_&U@w
long nStartPos; //File Snippet Start Position #_)<~
long nEndPos; //File Snippet End Position O3H dPQ
int nThreadID; //Thread's ID ?QuD:vck
boolean bDownOver = false; //Downing is over hJ[Z~PC\T0
boolean bStop = false; //Stop identical !Wn^B|
FileAccessI fileAccessI = null; //File Access interface @}sxA9a
eiE36+'>b
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t@dv$W2 "
{ p2Yc:9r9+A
this.sURL = sURL; (Q~ p"Ch
this.nStartPos = nStart; GcXh V
this.nEndPos = nEnd; _Ec9g^I10
nThreadID = id; V80BO#Pk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @,btQ_'X
} "`;$wA
AG?cI@',
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public void run() J${'?!N
{ B.)!zv\{
while(nStartPos < nEndPos && !bStop) 4#jW}4C{
{ XNODDH
z^;0{q,
?4p\ujc
try{ S3Q^K.e?
URL url = new URL(sURL); Q7u/k$qN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F\LAw#IJ
httpConnection.setRequestProperty("User-Agent","NetFox"); (t$jb|Oa
String sProperty = "bytes="+nStartPos+"-"; O"%b@$p\L
httpConnection.setRequestProperty("RANGE",sProperty); "9Q @&C
Utility.log(sProperty); >/W
k'H+l]=
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InputStream input = httpConnection.getInputStream(); ;h|zNx0
//logResponseHead(httpConnection); aNd6#yU$
v D"4aw
ollJ#i9
byte[] b = new byte[1024]; O{YT6&.S0
int nRead; -|Z[GN:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O}$@|w(8;
{ V5ve
nStartPos += fileAccessI.write(b,0,nRead); 6}b1*xQ
//if(nThreadID == 1) b@6hGiqx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {w/{)BnPG
} 8OV;&Z,x
W|C>X=zTi
^r4@C2#vzJ
Utility.log("Thread " + nThreadID + " is over!"); l~_]k
bDownOver = true; SQ$|s%)oB
//nPos = fileAccessI.write (b,0,nRead); gXrXVv<)yw
} qIXo_H&\C
catch(Exception e){e.printStackTrace ();} ,# i@jB
} T9&-t7:
} 5~BM+ja
$@WqM$
Tf0"9
//打印回应的头信息 H rMH
public void logResponseHead(HttpURLConnection con) Gcu[G]D
{ }bkQr)us
for(int i=1;;i++) Vp"=8p#k
{ \L6kCY
String header=con.getHeaderFieldKey(i); k 5~#_D>
if(header!=null) h`{agWB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [9}D+k F
Utility.log(header+" : "+con.getHeaderField(header)); >d/DXv 3
else W>^WNo3YQ$
break; & B CA
} G&2UXr3
} q$#5>5&
E[IjeJB5
h\]D:S
public void splitterStop() 3u&>r-V6Fn
{ `1O<UJX
bStop = true; 397IbZ\
} l*l?aI
3vcKK;qCB
]x;*Z&
} =I(F(AE
yUUg8xbpxF
|IN{8
/* $G\IzK
**FileAccess.java #Qir%\*V
*//文件访问(定位，写) Ll2yJ .C4
package NetFox; q:iB}ch5R
import java.io.*; Bsr;MVD
Npr<{}ZE
M/Twtq-`H
public class FileAccessI implements Serializable{ ON.1'Wk?
!L|}/u3v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 lla?;^,
RandomAccessFile oSavedFile; %1\MW+
long nPos; "W"2Y(
\ytF@"7
s|cL mL[
public FileAccessI() throws IOException k'(d$;Jgr
{ w# iezo. 0
this("",0); J>o%6D
} :"ta#g'
47/14rY 2
+VE] .*T
public FileAccessI(String sName,long nPos) throws IOException 0Z11V9Jk
{ Q;h6F{i
oSavedFile = new RandomAccessFile(sName,"rw"); vV(?A
this.nPos = nPos; }=7? & b
oSavedFile.seek(nPos); 2:8p>^g=
} CyHaFUbZ
t_Q\uo}
~_XK<}SK
public synchronized int write(byte[] b,int nStart,int nLen) h?D>Dfeg%
{ %U<1]
int n = -1; &/\Q6$a
try{ l-mt{2
oSavedFile.write(b,nStart,nLen); 1xf Pe#
n = nLen; )XFaVkQ}
} be->ofUYgs
catch(IOException e) $FJf8u`
{ << XWL:
e.printStackTrace (); 9ZYT#h
} ;A\SbLM
Y8s.Q
K{vn[}
return n; .%x1%TN
} W Z_yaG$U
&{gD(QG
9w"kxAN
} mS]&
ge[hAI2I
9f|+LN##
/* F<YXkG4pO
**SiteInfoBean.java ||}'
*/ =N~*`5|rk
package NetFox; \LEUreTn
g><*qd?t
izvwXC
public class SiteInfoBean { ';vLj1v
}G3:QD
9&O7F}VP2
private String sSiteURL; //Site's URL ?D,8lABkT
private String sFilePath; //Saved File's Path >[qoNy;
private String sFileName; //Saved File's Name qhQeQ
private int nSplitter; //Count of Splited Downloading File Zr#\>h'c
&BZjQK
UG,<\k&
public SiteInfoBean() \@eaSa
{//nSplitter的缺省值为5 /=i+7^
//default value of nSplitter is 5 "NMSLqO
this("","","",5); gK#G8V-,
} "C~Zl&3
<J o\RUx
@ )2<$d
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "<Q,|Md
{ >u0B ~9_E
sSiteURL= sURL; qF? n&>YG
sFilePath = sPath; 6");NHE
sFileName = sName; ^77Q4"{W
this.nSplitter = nSpiltter; _@/nc:)H
I #bta
J+:gIszsWT
} >s;>"]
?E6C|A$I
cq0#~20
public String getSSiteURL() +\yQZ{4'@
{ [+2iwfD
return sSiteURL; M/LC:,
} Zk*!,,P!
"T~ce@
Er!s\(h
public void setSSiteURL(String value) Rch?@O#J
{ )1ct%rue
sSiteURL = value; \-Ipa59U
} H\^zp5/
Ty5}5)CRZ
vdFP ^06
public String getSFilePath() Q^@z]Sc[
{ wticA#mb
return sFilePath; >&?k^nI}J
} [IRWmN-
6^#@y|.
o'*7I|7a
public void setSFilePath(String value) g?1! /+
{ c>)_I
sFilePath = value; _!:*&{
} Xt$o$V
C#tY};t
277Am*2
public String getSFileName() 7|Bg--G1
{ 8;q2W F{AX
return sFileName; C9Xj)5k@R
} 6 66f;h
Og E<bw
vNIQ1x5Za
public void setSFileName(String value) YCI-p p
{ Pgo^$xn'6
sFileName = value; h3BDHz,
} qP4vH]
6_a~ 4_#
<"HbX
public int getNSplitter() <UE-9g5?G
{ 3OvQ,^[J4
return nSplitter; 2(s-8E:
} ;Svs|]d
}Q#3\z5
-8pQI
public void setNSplitter(int nCount) 6U?z
{ grbUR)f<?-
nSplitter = nCount; ?_BK(kL_
} yRtxh_wr9
} [7sy}UH
T^1]|P
1J?x2
/* 90[?)s
**Utility.java & G8tb>q<V
*/ #Ks2a):8
package NetFox; =1e>$E#
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9yWQ}h
public class Utility { R\ZyS )~l
_I A{I
e)):U
public Utility() W"&Y7("y
{ ITr@;@}c]
kr{eC/Q"
^wTod\y
} xu(N'l.7&
M9dOLM.
//线程睡眠 ]O 8hkGa
public static void sleep(int nSecond) Ce-D^9kC
{ E@N& Y1t
try{ se]q~<&
Thread.sleep(nSecond); y{O817 \
} p0bMgP
catch(Exception e) 5* 3T+OK
{ fXfO9{E
e.printStackTrace (); l6z}D;4
} {wy#HYhv
} \`N<0COP
QsC6\Gt#
//日志 _7P#?:h
public static void log(String sMsg) rFl6xM;F
{ n[tES6u
System.err.println(sMsg); ZT1IN6;8W
} ,I^:xw_
#a|.cm>6
uX8yS|= *
public static void log(int sMsg) ]s<}'&
{ na-mh E,H
System.err.println(sMsg); p6|RV(?8
} MFqM6_
} /KLs+^c5
9n!IdqKN
}n[<$*W^
/* k%2Rv4)hU
**TestMethod.java 2GW.'\D
*/ OHyBNJ
package NetFox; ^!yJ;'H\
ai@hQJ*
l?J|Ip2W
public class TestMethod { WIkr0k
D N#OLk
V+- ]txu|
public TestMethod() ON q=bI*
{ ///xx/weblogic60b2_win.exe *Iir/6myM
try{ Aat-938FP6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^Z`?mNq9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); lVR a{._m
SiteFileFetch fileFetch = new SiteFileFetch(bean); [)L)R`
fileFetch.start(); l.@&B@5F
} -er8(snDQ
catch(Exception e){e.printStackTrace ();} Yj/[I\I"m
,p7W4;?4
4y|%Oj
} hQPNxpe
Ks_B%d
+204.Yj?D
public static void main(String[] args) k<i#agq
{ zd-qQ.j0
new TestMethod(); >2[nTfS
} \\{+t<?J
} RZrQ^tI3"
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