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)); 18jJzYawh
} S,XKW(5
for(int i=0;i<nEndPos.length-1;i++) YDW|-HIF
{ jg?bf/$s
nEndPos = nStartPos[i+1]; %W(^6p!
} k<!<<,Z
nEndPos[nEndPos.length-1] = nFileLength; (9E( Q*J5x
} / HL_$g<
} \/n+j!
Z A[)
00"CC
//启动子线程 /\d(c/,4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; V- /YNRV
for(int i=0;i<nStartPos.length;i++) AH|Y<\
{ '|_/lz$h
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MBlBMUJk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5lGQ#r
nStartPos,nEndPos,i); 7"#f!.E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d)\2U{
fileSplitterFetch.start(); |88CBiu}
} uj)yk*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ubi~%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 55^tfu
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W8y$Ve8m
nEndPos = " + nFileLength); r|<6Aae&
// fileSplitterFetch[nPos.length-1].start(); r5[4h'f
6s5yyy=L%~
Nfg{,/O
//等待子线程结束 c+~LpSQ
//int count = 0; =x1Wii$`
//是否结束while循环 #,TELzUVE
boolean breakWhile = false; -;vT<G3
N\'TR6_,b
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while(!bStop) X{`1:c'x
{ Oo1ecbY
write_nPos(); (#If1[L
Utility.sleep(500); ~}K{e
breakWhile = true; 5?w.rcN[j
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|U EC
for(int i=0;i<nStartPos.length;i++) "-P/jk
{ <1K7@Tu
if(!fileSplitterFetch.bDownOver) 3-iD.IAUm@
{ IytDvz*|
breakWhile = false; XC2FF&B&
break; ,m:L2 -J@
} Ch t%uzb,
} Cs#w72N
if(breakWhile) JYQ.EAsr!
break; "H$@b`)
\ADLMj`F|
L:pUvcAc?
//count++; O>%$q8x@i
//if(count>4) m<3w^mww
// siteStop(); tvGlp)?.
} []gRfM]$&
sBU_Ft
N}DL(-SQ3
System.err.println("文件下载结束！"); JCD?qeTg
} or!!s 5[d
catch(Exception e){e.printStackTrace ();} !9D1 Fa
} y6FKg)
)b9_C O}
r8,om^N6
//获得文件长度 @D]lgq[
public long getFileSize() yPN+W8}f
{ C `6S}f,
int nFileLength = -1; Mb.4J2F?
try{ Im+7<3Z
URL url = new URL(siteInfoBean.getSSiteURL()); !b63ik15O~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WL1\y|
httpConnection.setRequestProperty("User-Agent","NetFox"); $ser+Jt=
!W /C[$E
*QE"K2\5
int responseCode=httpConnection.getResponseCode(); tDt :^Bc
if(responseCode>=400) <h@]Ri
{ ^Q\XGl
processErrorCode(responseCode); qe%V#c
return -2; //-2 represent access is error CdL.?^
} ot }6D
#q;z8 @
|z*>ixK
String sHeader; #x)8f3I
(hN?:q?'
zSXA=
for(int i=1;;i++) Ha)np
{ $w/E9EJ)3A
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mX;H((
//Utility.log(in.readLine()); B`1kGEx .
sHeader=httpConnection.getHeaderFieldKey(i); |vz9Hs$@l
if(sHeader!=null) j^nu|
{ \c%g M1
if(sHeader.equals("Content-Length")) `[Sl1saZ$S
{ $@.jZ_G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e2wvc/gG6
break; F&az":
} h/?6=D{
} SY T$3|a
else ;MPKJS68@
break; 9go))&`PJL
} oj@g2H5P
} E-SG8U;
catch(IOException e){e.printStackTrace ();} `tVy_/3(9
catch(Exception e){e.printStackTrace ();} :c:V%0Yji
.&|L|q}
(NaK3_
Utility.log(nFileLength); "V}qf3qU
I_>`hTiR
v2>Z^
return nFileLength; M1{(OY(G
} s[X B#)H4
CA*~2|
#xp(B5
//保存下载信息（文件指针位置） m9t$h
private void write_nPos() U&W"Ea=R/
{ `0@z"D5c
try{ YPEnNt+
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y.-S=Y
output.writeInt(nStartPos.length); T5e^J"
for(int i=0;i<nStartPos.length;i++) W;TJenv
{ H,K`6HH
// output.writeLong(nPos); ?1w"IjUS
output.writeLong(fileSplitterFetch.nStartPos); B;W(iI
output.writeLong(fileSplitterFetch.nEndPos); X8R1a?
} pkk4h2Ah
output.close(); GTAf
} (a#pvEY
catch(IOException e){e.printStackTrace ();} 0Oap39
catch(Exception e){e.printStackTrace ();} Y;_T=L
} -Qb0:]sV#
J\A8qh8
/b%Q[ Ck_
//读取保存的下载信息（文件指针位置） I`^YAbnb
private void read_nPos() X"<|Z]w
{ @GeHWv
try{ :1_mfX
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bV6V02RF
int nCount = input.readInt(); 2Y+:,ud\
nStartPos = new long[nCount]; a+ GJVJ
nEndPos = new long[nCount]; doLNz4W
for(int i=0;i<nStartPos.length;i++) wW5Yw i
{ E9$H nj+m
nStartPos = input.readLong(); B*79qq
nEndPos = input.readLong(); C6^j#rl
} D^?_"wjW
input.close(); MLS;SCl
} u)~s4tP4
catch(IOException e){e.printStackTrace ();} 9rcI+q=E
catch(Exception e){e.printStackTrace ();} Y[G9Vok VX
} >r}Vf9 5[N
]sL45k2W
BS2?!;,8
private void processErrorCode(int nErrorCode) N!c gN
{ S(t{&+Wc
System.err.println("Error Code : " + nErrorCode); +tUQ
} w}`3 d@
9XOyj5
z<<Tk.65
//停止文件下载 Gru ALx7
public void siteStop() c;!9\1sr
{ _yVPpA[a
bStop = true; 4f {+pf^R
for(int i=0;i<nStartPos.length;i++) c0[k T
fileSplitterFetch.splitterStop(); 6Xa.0(h
^73=7PZ
AP w6
} }N,>A-P
} e{!vNJ0`
//负责部分文件的抓取 H(> M
**FileSplitterFetch.java (oYW]c}G,
*/ =DMbz`t
package NetFox; 28oJFi]
UvBnf+,
ug&92Hdvy3
import java.io.*; XeU<^ [
import java.net.*; &HL{LnLP@/
oD0EOT/E
>FF1)~
public class FileSplitterFetch extends Thread { [hHG.
jVYH;B%%z
%g w{[ /[A
String sURL; //File URL 6?o>{e7n^
long nStartPos; //File Snippet Start Position 6mHhC?
long nEndPos; //File Snippet End Position asz?p\k:bC
int nThreadID; //Thread's ID RGp'b
boolean bDownOver = false; //Downing is over 2 ~-( A
boolean bStop = false; //Stop identical n(R_#,Hs
FileAccessI fileAccessI = null; //File Access interface w1i?#!|
)eR$:uO
dtTlIhh1V
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~6d5zI4\
{ 9p*-?kPb
this.sURL = sURL; =l,#iYJP8
this.nStartPos = nStart; q[c Etp28h
this.nEndPos = nEnd; ^:z7E1~
nThreadID = id; YiZx{5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 v<&v]!nF
} sykFSPy`'
e/94y6*>
K7RKF$Z\
public void run() oAz<G
{ W~NYU
while(nStartPos < nEndPos && !bStop) 7$_ :sJ
{ 7I3:u+
.bfST.OA
?Ib}
try{ b:Dg}
URL url = new URL(sURL); \h#9oPy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (\& 62B1
httpConnection.setRequestProperty("User-Agent","NetFox"); Vp7b4n<
String sProperty = "bytes="+nStartPos+"-"; zlkWU
httpConnection.setRequestProperty("RANGE",sProperty); -*3(a E
Utility.log(sProperty); \EI#az=I
B_&^ER5j
rzT{-DZB[4
InputStream input = httpConnection.getInputStream(); all*P #[X
//logResponseHead(httpConnection); ]M\q0>HoJ
V6*?$o
8ds}+TtbY
byte[] b = new byte[1024]; )X%oXc&C|
int nRead; P` ]ps?l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8\_*1h40s
{ qTy v.#{y
nStartPos += fileAccessI.write(b,0,nRead); hr~.Lj5^W
//if(nThreadID == 1) @C_ =*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2sun=3qb
} 4Py3I9
UkfA}b^@v
4)nt$fW
Utility.log("Thread " + nThreadID + " is over!"); tN!Bvj:C[M
bDownOver = true; 3:AU:
//nPos = fileAccessI.write (b,0,nRead); #Fzb8Yo
} mz-N{>k
catch(Exception e){e.printStackTrace ();} @_Sp3nWdu
} ^ZVOql&
} Yb9cW\lr
0BDS_Rx
w4A#>;Qu*
//打印回应的头信息 PWG;&ma
public void logResponseHead(HttpURLConnection con) 7LdzZS0OM
{ fTgbF{?xh
for(int i=1;;i++) }4KW@L[g
{ '!@A}&]
String header=con.getHeaderFieldKey(i); 8Fx]koP.
if(header!=null) |^!Vo&T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /.@x 4cdS
Utility.log(header+" : "+con.getHeaderField(header)); ?Cc :)
else 3):?ZCw7y
break; ^O \q3HA_4
} :D4];d>1
} 5M.Red.L
DaDUK?
UM\}aq=,
public void splitterStop() yxY h?ka
{ 'M-)Os"
bStop = true; y#e ?iE@
} AysL-sqR
2Pz5f
D6:DrA:
} kQ[Jo%YT?E
I4:rie\hjC
_.-#E$6s#q
/* N'a?wBBR
**FileAccess.java tWX7dspx/
*//文件访问(定位，写) wPQ&Di*X}
package NetFox; ^XNw$@&',
import java.io.*; -;ER`Jqs,
z L8J`W
Yx 3|G
public class FileAccessI implements Serializable{ /N%zwj/*
g/B\ObY
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v^\JWPR/
RandomAccessFile oSavedFile; MYu`c[$jZ
long nPos; ydyG}XI7V
cdDY]"k
SctJxY(}!
public FileAccessI() throws IOException 1yJ75/
{ SdSgn|S
this("",0); bq: [Nj
} n{$}#NdV
TH>,v
=-m(\}
public FileAccessI(String sName,long nPos) throws IOException OQ,}/
{ W[fT R?n
oSavedFile = new RandomAccessFile(sName,"rw"); Nuo^+z E
this.nPos = nPos; EoKo
oSavedFile.seek(nPos); LS{bg.e
} 1]Lhk?4t
BPh".RJ
HM 90Sb
public synchronized int write(byte[] b,int nStart,int nLen) ~;!BDLMC6
{ V07VwVD
int n = -1; @"0uM?_)-
try{ )# p.`J
oSavedFile.write(b,nStart,nLen); .Nk}Z9L]k
n = nLen; 3jXR"@Z-
} J ZA*{n2
catch(IOException e) e|JIrOnc
{ e) ]RA?bF
e.printStackTrace (); %6N)G!P
} [0wP\{%
blUY.{NN3
l\_x(BH
return n; "A]?M<R
} o:H'r7N
Y}S.37|+^
3hH>U%`-
} 9QC< E|
D(!;V KH
O%52V|m}{
/* *^uGvJXF
**SiteInfoBean.java :Jm!=U%'Z
*/ ^]i" H|(x
package NetFox; ?P%|P
<o~t$TH
&{BBxv)y
public class SiteInfoBean { k~{Fnkt
>n1h^AW
[#IBYJ.6
private String sSiteURL; //Site's URL [;*\P\Xih
private String sFilePath; //Saved File's Path 40R"^*
private String sFileName; //Saved File's Name VZHr-z$6n
private int nSplitter; //Count of Splited Downloading File Bpm,mp4g\#
0e)lY='^_
}M^_Z#|,
public SiteInfoBean() xUQdVrFU
{//nSplitter的缺省值为5 z1kBNOr
//default value of nSplitter is 5 g ,`F<CF9
this("","","",5); )sRN!~
} j{)fC]8H
U&`6&$]
v: giZxR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !;TR2Zcn
{ kp'b>&9r
sSiteURL= sURL; J9NsHr:A[
sFilePath = sPath; ";756'>
sFileName = sName; JR])xPI`
this.nSplitter = nSpiltter; Kq$:\B)<c
cD5w| rm?i
WUzSlZq
} hK Fk$A
5QKRI)XpZ
mlD%d!.
public String getSSiteURL() 04P.p6
{ c^rC8E
return sSiteURL; ={\![{L
} DE5d]3B
C?8PT/
NS h%t+XU]
public void setSSiteURL(String value) 3T"2S[gT
{ Pa3{Ds
sSiteURL = value; I+*osk
} 0K&_D)
>ze>Xr'm5=
BHEs+e0
public String getSFilePath() xT:qe
{ dUI3erO
return sFilePath; 3(aRs?/O
} MgHOj
D% oueW
bh{E&1sLh
public void setSFilePath(String value) <_=JMA5
{ G}182"#4
sFilePath = value; KrJ5"1=
} #c6ui0E%;t
lq~GcM
"(Mvl1^BT
public String getSFileName() >s;oOo+5
{ EV:_Kx8fP
return sFileName; Vp|2wlFE-
} k&WUv0
JtSuD>H`"
@P*ylB}?Q
public void setSFileName(String value) ~o:rM/!Ba
{ Lc58lV=
sFileName = value; P;^y|0Nm
} 8w03{H 0
E7V38Z
MomLda V9Q
public int getNSplitter() _TtX`b_Z
{ mfj4`3:NV
return nSplitter; \El|U#$u'
} /7c2OI=\
<sm#D"GpP
r3n=<l!Jr
public void setNSplitter(int nCount) UAnB=L,.\
{ fx]\)0n
nSplitter = nCount; ~C%2t{"
} _`TepX R
} Rbx97(wK
kJHr&=VO~
VI(RT-S6
/* i6-wf Gs;
**Utility.java Mr$# e
*/ aeEw#
package NetFox; 3Cq6h;!#
^RYn8I
);0<Odw%.
public class Utility { =6.8bZT\
qlz( W
83mlZ1jQz
public Utility() NYWG#4D
{ m"96:v
;M%oQ>].[
u)<Ysx8G
} l0qdk#v
pYYqGv^oa
//线程睡眠 AM>Yj
public static void sleep(int nSecond) ck(CA(_
{ j)g_*\tQ
try{ i58ZV`Rk`
Thread.sleep(nSecond); Zkf 3t>[
} *54>iO- c
catch(Exception e) ^</65+OT+
{ r~ZS1Tp
e.printStackTrace (); mle_*Gy8
} r^?)F?n!
} L!CX&
uPa/,"p
//日志 F?*Dr
public static void log(String sMsg) 43vGgGW
{ v_y!Oh?EG
System.err.println(sMsg); {Q{lb(6Ba
} z7OZ4R:
0!9?H1>
^+(A&PyP?
public static void log(int sMsg) y0/WA4,
{ "6NFe!/Y$*
System.err.println(sMsg); FQ;4'B^k]
} <dju6k7uz
} #E- VW
k98< s
8QkWgd7y
/* kvMk:.
**TestMethod.java ?b!CV
*/ tebWj>+1c
package NetFox; N&6_8=3z
Z7tU0
.`oJcJ
public class TestMethod { 8@Egy%_
/#S4espE
:z0s*,QH
public TestMethod() LydbP17K}
{ ///xx/weblogic60b2_win.exe \_m\U.*
try{ w.4u=e >Z4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \zk?$'d
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :FX'[7;p
SiteFileFetch fileFetch = new SiteFileFetch(bean); +-Z"H)
fileFetch.start(); ,pQ'w7
} MgJ%26TZ
catch(Exception e){e.printStackTrace ();} DhtU]w}
!Iw{Y'
{]t\`fjrg
} )GiFkG
p)?qJ2c|
Cm,*bgX
public static void main(String[] args) ltCwns
{ %8}WX@SB
new TestMethod(); ua]\xBWx
} YtwmlIar`
} \Dvl%:8
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