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)); bpgvLZb>s
} z}z 6Vg
for(int i=0;i<nEndPos.length-1;i++) T0TgV
{ ($or@lfs
nEndPos = nStartPos[i+1]; =9yh<'583
} T j(MIFi|5
nEndPos[nEndPos.length-1] = nFileLength; Z`]r)z%f
} ms%RNxU4:
} hteAuz4H
4}xw&x
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//启动子线程 0Fc^c[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0ub0[A
for(int i=0;i<nStartPos.length;i++) >K;DBy*
{ =IH~:D\&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o|G[/o2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), XDQ5qfE|
nStartPos,nEndPos,i); c$P68$FB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A}3dx!?7j
fileSplitterFetch.start(); 7U647G(Sg
} `p'682xI
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +S6(Fvp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;lP/hG;`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ? dh
nEndPos = " + nFileLength); ;k|U2ajFJ
// fileSplitterFetch[nPos.length-1].start(); D8 BmC
{3`cSm6c
RIdh],-
//等待子线程结束 +=MN_
//int count = 0; N> jQe
//是否结束while循环 C116c"
boolean breakWhile = false; j@u]( nf
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%5$)w;p.$'
while(!bStop) mJNw<T4!/
{ E^4}l2m_
write_nPos(); O;lGh1.
Utility.sleep(500); WRov7
breakWhile = true; [jEZ5]%
iu.v8I;<
B? Z_~Bf&
for(int i=0;i<nStartPos.length;i++) 9T#${NK
{ %EH{p@nM&-
if(!fileSplitterFetch.bDownOver) ~YRG9TK
{ oH='\M%+
breakWhile = false; zQ~ax!}R
break; Ms 3Sri
} u*=8s5Q[
} 572{DC&T
if(breakWhile) [nASMKK0
break; mgE r+
).3riR
363KU@`
//count++; e|}B;<
//if(count>4) B",;z)(%
// siteStop(); z_8lf_N
} .+(R,SvN%<
%k'>bmJ
<&RpGAk%I
System.err.println("文件下载结束！"); \2))c@@%
} \,S4-~(:!
catch(Exception e){e.printStackTrace ();} /b7]NC%
} gY&WH9sp?9
bRD-[)
)uu(I5St
//获得文件长度 +L|x^B3
public long getFileSize() b/"gUYo
{ >@)p*y.K
int nFileLength = -1; $f?GD<}?7r
try{ wZfY~
URL url = new URL(siteInfoBean.getSSiteURL()); |Kb m74Z%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FBxg^g%PB@
httpConnection.setRequestProperty("User-Agent","NetFox"); MfZamu5+F
bae;2| w
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int responseCode=httpConnection.getResponseCode(); 3Fw7q"
if(responseCode>=400) :cvT/xhO
{ G=/^]E
processErrorCode(responseCode); #y-R*4G
return -2; //-2 represent access is error Du #>y!
} Cto>~pV
c] -
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String sHeader; E#R1
o3$dl`'
I0*N "07n
for(int i=1;;i++) X-*LA*xbN
{ fjCFJ_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); d$^@$E2f
//Utility.log(in.readLine()); y* :C~
sHeader=httpConnection.getHeaderFieldKey(i); U@9v(TfV
if(sHeader!=null) &F:%y(;{Y
{ WjguM
if(sHeader.equals("Content-Length")) :T{VCw:*
{ gBr/Y}I
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1~Z
break; K@%gvLa\
} xX|f{)<
} =QK ucLo
else 2H1 [oD[
break; _(-i46x}
} R"j<C13;%
} CG;+Z-"X
catch(IOException e){e.printStackTrace ();} g:Q:cSg<
catch(Exception e){e.printStackTrace ();} {n&GZG"f
Id1de>:;
orOq5?3
Utility.log(nFileLength); EU Z7?4o
~)F_FS
osc A\r
return nFileLength; fZoQQ[s
} :k-@w5(
g/(BV7V
*eGG6$I
//保存下载信息（文件指针位置） Zv2]X-
private void write_nPos() G5%k.IRz
{ _0BQnzC=
try{ 2}XxRJ0
output = new DataOutputStream(new FileOutputStream(tmpFile)); c/^l2CJ0
output.writeInt(nStartPos.length); 4 |bu= T
for(int i=0;i<nStartPos.length;i++) Y9I|s{~
{ h^v#?3.@
// output.writeLong(nPos); Ii#+JY0k
output.writeLong(fileSplitterFetch.nStartPos); l$[,V:N
output.writeLong(fileSplitterFetch.nEndPos); 1]9l SE!E7
} #0?3RP
output.close(); y|=KrvMHJ
} R;pIi/yDRe
catch(IOException e){e.printStackTrace ();} BNe>Lko
catch(Exception e){e.printStackTrace ();} ~^'WHuzPy
} ?gBFfi
~k%XW$cV
ayh235>a(
//读取保存的下载信息（文件指针位置） -BSO$'{7
private void read_nPos() .K1wp G[4
{ FY-eoq0O3
try{ 9kwiG7V1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Nv|0Z'M
int nCount = input.readInt(); f|ERZN`uB
nStartPos = new long[nCount]; \GV'{W+o2
nEndPos = new long[nCount]; ;O|u`fAqT
for(int i=0;i<nStartPos.length;i++) Rn`DUYg
{ 9R">l5u
nStartPos = input.readLong(); 4 L 5$=V
nEndPos = input.readLong(); JP(0/?Q
} | #b/EA9
input.close(); qQIX:HWDKZ
} 8)MWC:
catch(IOException e){e.printStackTrace ();} !@*= b1
catch(Exception e){e.printStackTrace ();} {6%-/$LX
} scTt53v^
4;@L#Pzt
Z +O<IF%
private void processErrorCode(int nErrorCode) <EdNF&S-
{ C9_[ke[1D
System.err.println("Error Code : " + nErrorCode); xB]^^NYE=
} a_]l?t
CMyz!jZ3
K"hnGYt?
//停止文件下载 >^IUS8v
public void siteStop() ktRGl>J
{ *yY\d.6(
bStop = true; GZHJ4|DK
for(int i=0;i<nStartPos.length;i++) u%6b|M@P
fileSplitterFetch.splitterStop(); LM 1Vsh<
.;S1HOHz4
d^v.tYM$N
} k2.k}?w!JO
} L4ct2|w}ul
//负责部分文件的抓取 yY*(!^S
**FileSplitterFetch.java Z$r7Hi
*/ ur7S K(#
package NetFox; (Q&O'ng1
@6%7X7m
}$sTnea
import java.io.*; mi7~(V>
import java.net.*; KfYT
vT @25
W`P>vK@=
public class FileSplitterFetch extends Thread { :."6g)T
I[?bM-
sl(go^
String sURL; //File URL ic4hO>p&
long nStartPos; //File Snippet Start Position 4@Z!?QzW
long nEndPos; //File Snippet End Position E$&bl
int nThreadID; //Thread's ID +WKN&@
boolean bDownOver = false; //Downing is over KfPgj
boolean bStop = false; //Stop identical y&eU\>M
FileAccessI fileAccessI = null; //File Access interface UR S=1+
rQ6>*0xL_
Pp_? z0M
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .>~er?-
{ U_.}V
this.sURL = sURL; m8G/;V[x
this.nStartPos = nStart; fU\;\
this.nEndPos = nEnd; a,)/D_{1
nThreadID = id; ksJ 1:_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ImD&~^-_<
} 'NCx<0*
VR%*8=
,rF!o_7
public void run() 'H4?V
{ B2KBJ4rI[1
while(nStartPos < nEndPos && !bStop) FFe{=H,=
{ J\p-5[E
B/^o$i
H0yM`7[y
try{ e 'F:LMX
URL url = new URL(sURL); sY?wQ:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rx@i.+
httpConnection.setRequestProperty("User-Agent","NetFox"); !,rF(pz
String sProperty = "bytes="+nStartPos+"-"; D~|q^Ms,%
httpConnection.setRequestProperty("RANGE",sProperty); 5*Qzw[[=
Utility.log(sProperty); Y7 K2@257
iel@"E 4
9'(m"c_
InputStream input = httpConnection.getInputStream(); "DH>4Q] d
//logResponseHead(httpConnection); U!K#g_}
QUfF>,[sv
W7@Vma`
byte[] b = new byte[1024]; &3xda1H
int nRead; ?^^TR/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uq7/G|
{ -j:yEZ4Oy
nStartPos += fileAccessI.write(b,0,nRead); GU9p'E
//if(nThreadID == 1) .2_xTt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m(EVC}Y
} :S7[<SwL
57]La^#
X?JtEQ~>
Utility.log("Thread " + nThreadID + " is over!"); p,uM)LD
bDownOver = true; h?}S|>9
//nPos = fileAccessI.write (b,0,nRead); T&bB8tQk
} a<>cbP
catch(Exception e){e.printStackTrace ();} l<ZHS'-;8
} 2R^Eea
} =UWW(^M#[:
{sj{3Iu
aGws?<1$
//打印回应的头信息 'z)cieFKP
public void logResponseHead(HttpURLConnection con) {yEL$8MC
{ <X5ge>.
for(int i=1;;i++) $fT#Wva-\d
{ ,t9CP
String header=con.getHeaderFieldKey(i); -mo4`F
if(header!=null) \%%M>4c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;XlCd[J<
Utility.log(header+" : "+con.getHeaderField(header)); Ex@}x#3
else qK~]au:C
break; +qqCk
} *P5/S8c
} Jw^my4
0dI7{o;<|
,OP\^
public void splitterStop() "?W8o[c+
{ !x||ObW\H
bStop = true; )nK+`{;@!
} i }Zz[b
r(_Fr#Qn
* kUb[
} 5lM 3In@
d-W*`:Q
TIaiJvo
/* gp H@FX
**FileAccess.java Qv;b$by3
*//文件访问(定位，写) 0AoWw-H6V
package NetFox; MBU4Awj
import java.io.*; No+BS%F5
&_j<!3*
A1z<2.R
public class FileAccessI implements Serializable{ 6Bexwf<u
\yLFV9P}EL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7uF @Xh
RandomAccessFile oSavedFile; w !<-e>
long nPos; IlI5xkJ(
Mii&doU
9y} J|z
public FileAccessI() throws IOException > %Hw008
{ 6x/o j`_[
this("",0); [biz[fm
} Zw%:mZN
+UTBiB R
S@~ReRew2
public FileAccessI(String sName,long nPos) throws IOException f}ch1u>
{ fjuPGg~
oSavedFile = new RandomAccessFile(sName,"rw"); *#@{&Q(Qh
this.nPos = nPos; IF<T{/MA
oSavedFile.seek(nPos); |%3>i"Y@AK
} 4$ah~E>,t
A8AeM`
1-.i^Hal
public synchronized int write(byte[] b,int nStart,int nLen) 7qWa>fX
{ /#L4ec-'
int n = -1; :`<MlX
try{ T8W^qrx.v
oSavedFile.write(b,nStart,nLen); qDfhR`1k
n = nLen; Z*v`kl
} }>3jHWxLc
catch(IOException e) at2)%V)
{ ?nE9@G5Gc
e.printStackTrace (); pE0@m-p
} E>2AG3)
?#nk}=;g8
~*~aFf5
return n; [i>D|X
} Eq8:[o
E(f|LG[I
R?}%rP+^e
} E5*pD*#
ltkA7dUbu
1$:O9{F
/* ygK,t*T20
**SiteInfoBean.java W&3,XFnI_
*/ 1:u~T@;" `
package NetFox; A,7* 52U
.hoVy*I
hVJ}EF0
public class SiteInfoBean { +HD2]~{EkL
U><$p{)
gzlRK^5
private String sSiteURL; //Site's URL Wrt5eYy
private String sFilePath; //Saved File's Path KmqgP`Cu
private String sFileName; //Saved File's Name d*@K5?O.
private int nSplitter; //Count of Splited Downloading File F+W{R+6
/L2.7`5
&k`lbkq
public SiteInfoBean() EYn9ln_]u
{//nSplitter的缺省值为5 v`@N R06
//default value of nSplitter is 5 A-M6MW
this("","","",5); /IHF
} c s:E^
G1I<B
};gcM@]]E
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]9wTAb
{ (I{+%
sSiteURL= sURL; Le,;)Nd
sFilePath = sPath; rV*Ri~Vx
sFileName = sName; `?d` #)Ck
this.nSplitter = nSpiltter; ?-<>he
$2Bll5!]
v9#F\F/
} RS2uk7MB
bY~V?yNgKM
Iy5)SZ'
public String getSSiteURL() "wxyY^"
{ H5CL0#I
return sSiteURL; H#T&7X_<
} WP^wNi ~>
v[jg|s&6"
3wPUP+)c7
public void setSSiteURL(String value) >3I|5kZ6
{ ^t`0ul]c
sSiteURL = value; 3aJYl3:0B
} }5Km \OI
@jZ1WHS_a
f'Oj01[
public String getSFilePath() 9j0o)]
{ <uo@k'
return sFilePath; jm'^>p,9G
} -"x@V7X
\J-D@b;
/U0,%
public void setSFilePath(String value) FvD/z;N
{ FU)=+m
sFilePath = value; :8]y*j
} I(z16wQ
*-E'$
@S&QxE^
public String getSFileName() &WS'Me
{ ;RMevVw|
return sFileName; "cvhx/\1#
} o;OEb
p]7IoO -@
|!CAxE0d$B
public void setSFileName(String value) :xY9eq=
{ 0aJcX)
sFileName = value; f7;<jj;w7
} .F/s(
%kP=VUXj
F><ficT
public int getNSplitter() CbOCL~ "
{ xX.{(er
return nSplitter; s'BlFB n
} 7s Gf_`Z
P]2V~I/X
&#!1 Y[e^
public void setNSplitter(int nCount) a/[)A _-
{ l;B
nSplitter = nCount; `(E$-m-~jH
} '*<I<? z;
} _s}`ohKvD
.d?LRf
O0eM*~zI
/* }:!X@C~
**Utility.java drbim8!q~
*/ oFsV0 {x%)
package NetFox; ju1B._48
|w5,%#AeO$
{TDZDH
public class Utility { ((=T E
dq0!.gBT2
/<"ok;Pu7
public Utility() K{ntl-D&y
{ /.>%IcK
Z,V<&9a;
K87yQOjPv
} F?qg?1vB|
s(r4m/
//线程睡眠 Q(x/&]7=V
public static void sleep(int nSecond) 0g#xQzE
{ Y+5aT(6O
try{ bGxHzzU}
Thread.sleep(nSecond); D&qJ@PR
} oqzWL~
catch(Exception e) bV+2U
{ aj<r=
e.printStackTrace (); PZI6{KOis
} m>*~tP
} }i^$ li@
`Q[NrOqe"
//日志 +zEyCx=8H
public static void log(String sMsg) hS&.-5v
{ )_6W@s
System.err.println(sMsg); 7}`FXB
} %AmyT
DVDzYR**4
$)d34JM
public static void log(int sMsg) Mh{>#Gs
{ Eqh*"hE7
System.err.println(sMsg); T wzpq1
} ;s-@m<
} tq51;L
LjIkZ'HuF
D0>Pc9
/* #$F*.vQSs+
**TestMethod.java kdaq_O:s
*/ M`E}1WNQ?]
package NetFox; 1MmEP
Qj$w7*U
wJ"]H!r0
public class TestMethod { 4um^7Ns)7
unKgOvtj
UD9JE S,
public TestMethod() L\V`ou
{ ///xx/weblogic60b2_win.exe -FJLM
try{ 9SJSUv:@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); rinTB|5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); WQbjq}RfI
SiteFileFetch fileFetch = new SiteFileFetch(bean); \[]?9Z=n
fileFetch.start(); G,<l}(tEG
} Z*-a=u%gl'
catch(Exception e){e.printStackTrace ();} T6."j_
#T@k(Bz{L
2\;/mQI2A
} z;_vl
|dDKO
ZT8LMPC
public static void main(String[] args) T|0d2aa
{ f>|<5zm#<
new TestMethod(); _ {6l}
} LF#[$ so{i
} B#cN'1c
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