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)); oCbpK
} I ld7}R
for(int i=0;i<nEndPos.length-1;i++) g1ytT%]
{ dGU8+)2cn
nEndPos = nStartPos[i+1]; Qne0kB5m
} (U_wp's
nEndPos[nEndPos.length-1] = nFileLength; qv$!\T
} h mds(lv7
} y #69|G
Ox~ 9_d
l0. FiO@_Q
//启动子线程 #3.\j"b
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z(rK^RT
for(int i=0;i<nStartPos.length;i++) rpSr^slr
{ JCNk\@0i*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :pb67Al29
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), i+1Qf
nStartPos,nEndPos,i); &>g~-s
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jFG5)t<D
fileSplitterFetch.start(); 0d";Hh:
} Y<aO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Li]k7w?H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); HS7_MGU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", G0pBR]_5z$
nEndPos = " + nFileLength); dqxd3,Z
// fileSplitterFetch[nPos.length-1].start(); gvGi%gq
W_%W%i|
r^Y~mq
//等待子线程结束 F3Dt7q
//int count = 0; ogJ<e_m
//是否结束while循环 ewym1}o
boolean breakWhile = false; ||XIWKF<n2
P.h.MA]
p/3BD&6
while(!bStop) kZv*rWAm
{ pqH4w(;
write_nPos(); f1J%]g!
Utility.sleep(500); R^6Zafp
breakWhile = true; R1/q3x
S/fW/W*/}
-bm,:Iy!
for(int i=0;i<nStartPos.length;i++) B4^`Sw
{ ssA7Dx:
if(!fileSplitterFetch.bDownOver) {_(+>v"eJ
{ p-Pz=Cx-
breakWhile = false; lJ&y&N<O
break; nj
} !k-` eJ|
} ~&KX-AC@
if(breakWhile) `m, Ki69.
break; `kPc!I7Y
nE7JLtbH
(6clq:c7j
//count++; ;'^, ,{
//if(count>4) )2V@p~k?
// siteStop(); iadkH]w
} Z2bUs!0
'hF@><sqk
v?)SA];
System.err.println("文件下载结束！"); #w*"qn#2Uz
} :,^>d3k
catch(Exception e){e.printStackTrace ();} /PW&$P1.]"
} Egf^H>,.M
e9:P9Di(b
!F$R+A+L
//获得文件长度 ^yJ:+m;6K
public long getFileSize() vI|As+`$d
{ Hk9U&j$
int nFileLength = -1; T>F9Hs W
try{ /AR]dcL@76
URL url = new URL(siteInfoBean.getSSiteURL()); D%gGRA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OpQ8\[X+
httpConnection.setRequestProperty("User-Agent","NetFox"); KuXkI;63J>
H`el#tt_
NnOI:X {
int responseCode=httpConnection.getResponseCode(); vYdlSe=6G
if(responseCode>=400) L {qJ-ln:
{ H;y}-=J+
processErrorCode(responseCode); !.-.#<<_a
return -2; //-2 represent access is error )8'jxiGs
} 4|f}F
kcY,vl
PUCx]5
String sHeader; ~K`1
IT&i,`cJ~F
&D*8l?A/1f
for(int i=1;;i++) jyQVSQs
{ J3IRP/*z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L;yEz[#xaT
//Utility.log(in.readLine()); g`3H(PVg
sHeader=httpConnection.getHeaderFieldKey(i); ]! )xr
if(sHeader!=null) LM6]kll
{ p:tN642
if(sHeader.equals("Content-Length")) ,]q%/yxi
{ L[]BzsIv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *~;8N|4<
break; x8/us
} >qpqQ; bm
} ^*>n4U
else ANb"oX c
break; u>o<tw%Y
} a.,i.2
} WjOH/$(
catch(IOException e){e.printStackTrace ();} Pb4q`!
catch(Exception e){e.printStackTrace ();} RH~sbnZ)F
o(Kcs-W2
=YHt9fb$c
Utility.log(nFileLength); Kj!Y K~~
TPK@*9rI
EneAX&SG
return nFileLength; )eq}MaW+j
} "K ?#,_
r<|nwFJ
]1}h8/
//保存下载信息（文件指针位置） (:OHyeNt
private void write_nPos() O<`,,^4w/
{ -l JYr/MSL
try{ xFwXW)
output = new DataOutputStream(new FileOutputStream(tmpFile)); 27iy4(4
output.writeInt(nStartPos.length); @h(!<Ux_
for(int i=0;i<nStartPos.length;i++) c'rd$
{ kwF]TO S
// output.writeLong(nPos); 7E(%9W6P
output.writeLong(fileSplitterFetch.nStartPos); 4>_d3_1sn
output.writeLong(fileSplitterFetch.nEndPos); waQtr,m)
} PkJcd->
output.close(); x.\XUJ4x
} lY,/W
catch(IOException e){e.printStackTrace ();} +5-fk>o
catch(Exception e){e.printStackTrace ();} ZpWu,1
} .[,6JU%
6|oWaA\gI
<I1y
//读取保存的下载信息（文件指针位置） 045\i[l=
private void read_nPos() :l`i4kx
{ I.9o`Q[8&
try{ h!Y?SO.b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Fx5ZwT t
int nCount = input.readInt(); bg1un@%!l
nStartPos = new long[nCount]; ph#efY`a:
nEndPos = new long[nCount]; nuxd S,
for(int i=0;i<nStartPos.length;i++) I%i:)6Un-y
{ j6og3.H-
nStartPos = input.readLong(); PY-+Bf
nEndPos = input.readLong(); 1LyT7h
} +f|6AeE
input.close(); [Auc*@
} m>YWxa
catch(IOException e){e.printStackTrace ();} %A2`&:ip
catch(Exception e){e.printStackTrace ();} x< S\D&
} AsAFUuI
n.Vtc-yZU
((cb4IX
private void processErrorCode(int nErrorCode) 6Hn)pD#U
{ lC2?sD$
System.err.println("Error Code : " + nErrorCode); P}l#VJWp
} 7V'Le2T'
6V P)$h8
h>|u:]I>
//停止文件下载 M5 `m.n<
public void siteStop() Qg>0G%cXU
{ ]?&H^"=
bStop = true; _NT[ ~M_Q
for(int i=0;i<nStartPos.length;i++) ~lk@6{`l|1
fileSplitterFetch.splitterStop(); ALAL( f`
6g|#ho1Bbs
@p6@a6N%
} %yvA
} J&_3VKrN
//负责部分文件的抓取 6qDfcs
**FileSplitterFetch.java [-]A^?yBM
*/ _25d%Ne0
package NetFox; e{JVXc[D
6WO7+M;z
~$*`cO
import java.io.*; 6e/7'TYwT
import java.net.*; RF!'K ko
ZYDWv/u
[ t$AavU.
public class FileSplitterFetch extends Thread { 4(8<w cL
FW5}oD(H
/W0E(8:C)
String sURL; //File URL {wv&t R;
long nStartPos; //File Snippet Start Position }1F6?do3&
long nEndPos; //File Snippet End Position &M=3{[
int nThreadID; //Thread's ID EIPnm%{1
boolean bDownOver = false; //Downing is over Ph Ttx(!
boolean bStop = false; //Stop identical %Gu][_.L
FileAccessI fileAccessI = null; //File Access interface jiq2x\\!
7$#rNYa,z
ke^d8Z.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %i3{TL
{ h(|;\~
this.sURL = sURL; wB2}uk7
this.nStartPos = nStart; =+4 _j
this.nEndPos = nEnd; w#<p^CS
nThreadID = id; egWx9xX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 o"\{OX
} :~i+tD
i3d y
KD=bkZ&
public void run() iU XM(]
{ N|$5/bV
while(nStartPos < nEndPos && !bStop) 9 R
{ EP(Eq
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Pr2;Kp
try{ I5Q~T5Ar
URL url = new URL(sURL); !%V*UR9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DiR'p`b~
httpConnection.setRequestProperty("User-Agent","NetFox"); <uC<GDO
String sProperty = "bytes="+nStartPos+"-"; E$R_rX4x
httpConnection.setRequestProperty("RANGE",sProperty); pkW5D
Utility.log(sProperty); VW~Xbyf
,0h3x$l)
{Y^c*Iqn
InputStream input = httpConnection.getInputStream(); +NT:<(;|i5
//logResponseHead(httpConnection); fQ1 0O(`g,
4ODX5If
cPJ7E
byte[] b = new byte[1024]; 4M7^ [G
int nRead; Op90NZI#K
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G\):2Qz!|
{ qJURPK
nStartPos += fileAccessI.write(b,0,nRead); Z7oaQ\fR
//if(nThreadID == 1) @f%wd2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )lOji7&e
} xh`Du|jvm
_\!0t
NU(^6
Utility.log("Thread " + nThreadID + " is over!"); !YIb
bDownOver = true; Q<C@KBiVE
//nPos = fileAccessI.write (b,0,nRead); VT Vm7l
} 9GaL0OWo
catch(Exception e){e.printStackTrace ();} ff[C'
} j37:
} C-&#r."L
5/k)\`
QY@nE
//打印回应的头信息 K: 4P;ApI
public void logResponseHead(HttpURLConnection con) uZ-`fcCjD
{ dhs#D:/{9
for(int i=1;;i++) 8>m1UONr
{ bYK]G+Ww
String header=con.getHeaderFieldKey(i); M{G$Pk8[
if(header!=null) 6z PV'~q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); K/~Y!?:Jr
Utility.log(header+" : "+con.getHeaderField(header)); C_C$5[~-:
else 9X.gg$P
break; C5cFw/',
} ')rD?Z9 ^
} VGfD;8]z
e`vUK.UoW
{;\%!I
public void splitterStop() <e[!3,%L
{ 3JTU^-S<
bStop = true; 9W$mDw6f
} E $<;@
??q!jm-m
FDl,Ey^r/
} A7.JFf>
O-?z' @5cI
f x%z|K
/* 3b,=
**FileAccess.java 1 iquHn
*//文件访问(定位，写) JtThkh'-"
package NetFox; {rs6"X^
import java.io.*; JE/l#Q!
O3!Ouh&
j\nE8WH
public class FileAccessI implements Serializable{ Pb*q;9
s8{-c^G:R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 on6<l
RandomAccessFile oSavedFile; .0?ss0~
long nPos; >\RDQ%z
Vvxa.B
'T6B_9GQ8
public FileAccessI() throws IOException Feh"!k <6k
{ </8be=e7p
this("",0); B#;s(O
} xh=FkY&d
gD,A9a(3
\\y}DNh
public FileAccessI(String sName,long nPos) throws IOException SIj6.RK
{ >t2]Ssi(
oSavedFile = new RandomAccessFile(sName,"rw"); XryQ)x(
this.nPos = nPos; h 3eGq:!9
oSavedFile.seek(nPos); e=0l<Rj
} >N :|Km\
Jii?r*"d
u XaL
public synchronized int write(byte[] b,int nStart,int nLen) uPM8GIvZX.
{ Wdei`u[
int n = -1; iH($rSE
try{ K]*g, s+
oSavedFile.write(b,nStart,nLen); *Pa2bY3:
n = nLen; p)K9ZI
} _G_ &Me0
catch(IOException e) 2O}s*C$Xav
{ c_R)P,P
e.printStackTrace (); L3-<Kop
} 50}.Xm@,BO
Q=)"om
^yzo!`)fso
return n; ;5,`Jpca
} g}\U, (
olUqBQ&ol
Ak<IHp^Q
} GGFar\ EzW
7I@9v=xV
XhJP87A
/* D5o+0R
**SiteInfoBean.java M6@'9E]|>
*/ V{7lltu
package NetFox; LAu+{'O\
~v{C6)
H]T2$'U6
public class SiteInfoBean { <lg"M;&Ht
{9m!UlTtw
o O{|C&A
private String sSiteURL; //Site's URL M]%!n3Fb
private String sFilePath; //Saved File's Path Bd N{[2
private String sFileName; //Saved File's Name ,6cbD
private int nSplitter; //Count of Splited Downloading File /ze_{{o
OuYE-x2]x"
;T"m[D
public SiteInfoBean() \'}/&PCkr
{//nSplitter的缺省值为5 #XYLVee,
//default value of nSplitter is 5 Jq$6$A,f
this("","","",5); 5VoOJ_hq
} yNb#Ia
+Y.uZJ6+
iuH8g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Z!s>AgH9u
{ Uy_}@50"l
sSiteURL= sURL; Wf+Cc?/4
sFilePath = sPath; V5(tf'
sFileName = sName; 3^iQe"P%a@
this.nSplitter = nSpiltter; D x>1y
#h #mOJ5
y(wqcDok|n
} !4b;>y=m
1o5Y9#7
t?#vb}_
public String getSSiteURL() 21)-:rS
{ hq&
return sSiteURL; 99+/W*C
} YiQeI|{oN
|=h)efo}
e{rHO,#A>
public void setSSiteURL(String value) 4E>/*F!
{ k_|v)\4B
sSiteURL = value; B1i!te}*
} Ep,0Z*j
bTo@gJkn
J:TI>*tn
public String getSFilePath() '#An+;x{
{ ,N@Icl
return sFilePath; YVg}q#
} !Z0rTC3d
-<}>YtB Q
OV@h$fg
public void setSFilePath(String value) MTFVnoZMQ_
{ ~jRk10T(B
sFilePath = value; mSfkyw.
} PE6u8ZAb"
l_q>(FoqA
r#6l?+W ;
public String getSFileName() coP$7Q .
{ g]PLW3
return sFileName; /cg]wG!n8
} 2Ws/0c
ph&H*Mc
R82Zr@_
public void setSFileName(String value) e5/DCz
{ x#e\H F
sFileName = value; ]JCB^)tM
} V.a]IkK'K
VOF:+o@.
YQ8x6AJ
public int getNSplitter() Gp3t?7S{T
{ %_J/&{6G
return nSplitter; YT%SCaU
} \$\(9!=
<+1w'-
ZD] '$
public void setNSplitter(int nCount) q$2taG}
{ *,*:6^t
nSplitter = nCount; !)*T
} fz?Wr: I
} /wRK[i
;KZ2L~ THG
kc(b;EA
/* PG~m-W+
**Utility.java {arjW3~M:
*/ o-i.'L)X
package NetFox; %?G.lej,x
s8I77._s
@j8L{FGnN
public class Utility { &7kSLat+9{
sbiDnRf
3SB7)8Id1
public Utility() /z-C :k\
{ HE<%d
r-"`Abev
#?d>S;)+
} Ywb)h^{!
{ZYCnS&?CL
//线程睡眠 (i~%4w=
public static void sleep(int nSecond) D '_#?%3^
{ eMd1%/[
try{ ~~E=E;9
Thread.sleep(nSecond); 8; N}d)*O
} owVUL~
catch(Exception e) 6!=9V0G~
{ |0pBBDw
e.printStackTrace (); UY& W]
} xupdjT%4
} ?[fl$EG
S5 oHe4#89
//日志 Hx/Vm`pRyX
public static void log(String sMsg) g_!xO2LH,8
{ }8KL]11b
System.err.println(sMsg); !-o||rt
} &CsBG?@Z|
&aht K}u
lukRFN>c"
public static void log(int sMsg) G uI sM
{ /OtQk-E
System.err.println(sMsg); iQR})=Q
} ?#y<^oNM
} [5#/&k{
{7szo`U2
x};g!FYfkB
/* sOHAW*+
**TestMethod.java 6Kc7@oO~
*/ NOr*+N\
package NetFox; -Z&{$J
2%%U)|39mB
aRKG)0=
public class TestMethod { 1{glRY'
,<WykeC
lMf5F8
public TestMethod() , &f20o
{ ///xx/weblogic60b2_win.exe )8>f
try{ vK>^#b3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {8Nd-WJ{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); XD>@EYN<X
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1pr_d"#4
fileFetch.start(); KT?s\w
} qq{N; C
catch(Exception e){e.printStackTrace ();} qk"=nAJX
jJnBwHp
bL[W.O0
} W8rn8Rh
.`=PE&xq
JEkVj']?
public static void main(String[] args) 9r*T3=u.S
{ a8U2c;
new TestMethod(); F!t13%yeu?
} 5Rp2O4Z
} 6$.Xj\zl
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