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)); )<5hga][~a
} 0/~{,
for(int i=0;i<nEndPos.length-1;i++) oSO~72
{ g(o^'f
nEndPos = nStartPos[i+1]; @[TSJi
} !]8QOn7=
nEndPos[nEndPos.length-1] = nFileLength; 0.U- tg0
} (J j'kW6G6
} E8aD[j[w
~x+&cA-0A2
Saks~m7,
//启动子线程 C&.Q|S2_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2FN#63
for(int i=0;i<nStartPos.length;i++) {C%f~j
{ IKp/xj[!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mU>lm7'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]C-a[
nStartPos,nEndPos,i); -_>E8PhM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tYhNr
fileSplitterFetch.start(); fDChq[LAn
} T>5N$i
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Et&PzDvU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ol8Yf.e_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pO N@
nEndPos = " + nFileLength); W;F=7[h
// fileSplitterFetch[nPos.length-1].start(); J2!)%mF$
c <X( S
[3v&j_
//等待子线程结束 y*-D
//int count = 0; )jw!,"_4
//是否结束while循环 ?oU5H
boolean breakWhile = false; \?$kpV
FMl_I26]
{YIVi:4q
while(!bStop) L,sXJ23.
{ I\=&v^]
write_nPos(); z'Ut9u
Utility.sleep(500); uA\KbA.c;U
breakWhile = true; I%mGb$Q
KP gzB^>
y# IUDnRJ
for(int i=0;i<nStartPos.length;i++) ca:Vdrw`
{ z2;<i|Ez0
if(!fileSplitterFetch.bDownOver) xv_Z$&9e>l
{ ]ia{N
breakWhile = false; 8@KGc )k
break; \Bl`;uXb
} YcM0A~<
} p<Vj<6.=?
if(breakWhile) y6>fK@K~
break; ~@D{&7@
#ahe@|E'Y
z+j3j2
//count++; 7C~g?1
//if(count>4) 4`:Eiik&p
// siteStop(); #D%l;Ae
} n7bML?f'
"]yfx@)_
OlX otp8
System.err.println("文件下载结束！"); wkD"EuW(
} I:] Pd
catch(Exception e){e.printStackTrace ();} hhJs$c(
} BHS8MV L@
@KU^B_{i
O?Qi
//获得文件长度 B1J2m^
public long getFileSize() }`_x%]EJ
{ _Hv@bIL'
int nFileLength = -1; 1sXVuto
try{ >NtJ)N*
URL url = new URL(siteInfoBean.getSSiteURL()); G=m18Bv{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S8;5|ya
httpConnection.setRequestProperty("User-Agent","NetFox"); T{lK$j
O/fm/
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int responseCode=httpConnection.getResponseCode(); vgKdhN2kI
if(responseCode>=400) >2#F5c67
{ +QEiY~i
processErrorCode(responseCode); YvFt*t
return -2; //-2 represent access is error }J_#N.y
} #$u7:p [t
^dKtUH/78G
(q=),3/<pU
String sHeader; P?<G:]W
E7@m& R
*YP;HL
for(int i=1;;i++) H) q_9<;
{ uL=FK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); x,QXOh\a
//Utility.log(in.readLine()); sE\Cv2Gx
sHeader=httpConnection.getHeaderFieldKey(i); 8LGNV&Edg
if(sHeader!=null) OJ<V<=MYZ
{ l'Uj"9r,
if(sHeader.equals("Content-Length")) +LaR_n[
{ (CY#B%*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g 4lk
break; 5:SS2>~g
} }%S#d&wh$_
} p u[S
else ZY8:7Q@P>
break; o=C'u
} =L,7~9
} )_1;mc8B
catch(IOException e){e.printStackTrace ();} Z':w X
catch(Exception e){e.printStackTrace ();} %kV #UzL
WI-I+0sE
_{?-=<V'_
Utility.log(nFileLength); m 8P`n
;~n^/D2.
n?8xRaEf
return nFileLength; 1oL3y;>iL
} h&:XO9dY
B[r04YGh
azl!#%
//保存下载信息（文件指针位置） vm8ER,IW)
private void write_nPos() A{ . A1
{ `~2I
try{ ed$w5dv
output = new DataOutputStream(new FileOutputStream(tmpFile)); M)sAMfuUw
output.writeInt(nStartPos.length); r!/<%\S
for(int i=0;i<nStartPos.length;i++) "_n})s f
{ f_|=EQ
// output.writeLong(nPos); M[7$F&&n
output.writeLong(fileSplitterFetch.nStartPos); rchKrw
output.writeLong(fileSplitterFetch.nEndPos); i?'|}tK
} $SdpF-'
output.close(); ,y[8Vz?:
} b}Xh|0`b+
catch(IOException e){e.printStackTrace ();} nc.:Wm6Mj
catch(Exception e){e.printStackTrace ();} |_%q@EID
} T<o8lL
*JiI>[
@8lT*O2j
//读取保存的下载信息（文件指针位置） yG,uD!N]|
private void read_nPos() ?~tx@k$;Es
{ f<3lxu
try{ 6K5mMu#4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qzii[Mf
int nCount = input.readInt(); 8T3Nz8Q7
nStartPos = new long[nCount]; V6fJaZ
nEndPos = new long[nCount]; O@`KGZEPY
for(int i=0;i<nStartPos.length;i++) ~SYW@o
{ 4z,/0
nStartPos = input.readLong(); h.5KzC S
nEndPos = input.readLong(); MCl-er"]D
} "$A5:1;
input.close(); %(:{TR
} o8N,mGj}
catch(IOException e){e.printStackTrace ();} P}"uC`036
catch(Exception e){e.printStackTrace ();} )8_MkFQe
} Y {|is2M9'
&M6Zsmo
u4DrZ-v
private void processErrorCode(int nErrorCode) R^@
{ Sn[/'V^$a
System.err.println("Error Code : " + nErrorCode); )&93YrHgC
} v>0} v)<v
wx_j)Wij6
(9v%66y
//停止文件下载 G$;cA:p-j
public void siteStop() oH(=T/{
{ P 4+}<5
bStop = true; }gKJ~9Jg
for(int i=0;i<nStartPos.length;i++) O[F
fileSplitterFetch.splitterStop(); /&zlC{:G92
1Hs'YzvY
TVAa/_y2`
} Fmzkbt~oe
} XUTsW,WC
//负责部分文件的抓取 DY1"t7 9E
**FileSplitterFetch.java Hh* KcIRX
*/ TEi1,yc
package NetFox; ?b\oM v5y
Z=(Tq1t
j eyGIY
import java.io.*; 0N_u6*@
import java.net.*; L)"CE].
j8;Uny9
X}`39r.
public class FileSplitterFetch extends Thread { z[0tM&pv
yacN=]SW5
u=7#_ZC9L
String sURL; //File URL piXL6V@c
long nStartPos; //File Snippet Start Position C0CJ;
long nEndPos; //File Snippet End Position &!B4v<#,U
int nThreadID; //Thread's ID 5. +_'bF|
boolean bDownOver = false; //Downing is over 4mnVXKt%.
boolean bStop = false; //Stop identical ^;wz+u4^l
FileAccessI fileAccessI = null; //File Access interface +g_m|LF
7MQxW<0
b;5 M$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !1Nh`FN
{ +NVXFjPC
this.sURL = sURL; Cm9#FA
this.nStartPos = nStart; 0U?(EJ
this.nEndPos = nEnd; 5RyxVC0<
nThreadID = id; /ACau<U]t
fileAccessI = new FileAccessI(sName,nStartPos);//定位 XHh*6Yt_ (
} A+(+PfU
DSlO.)dHu
g-4ab|F
public void run() 'l_F@ZO{(
{ 12tk$FcY8*
while(nStartPos < nEndPos && !bStop) Z:YgG.z"
{ `@{(ijg.
0/uy'JvWru
/q) H0b
try{ "G@(Cb*+T
URL url = new URL(sURL); #szIYyk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oj@=Cq':-
httpConnection.setRequestProperty("User-Agent","NetFox"); A0bR.*3
String sProperty = "bytes="+nStartPos+"-"; Tt4Q|"CJA
httpConnection.setRequestProperty("RANGE",sProperty); $3*y)Ny^
Utility.log(sProperty); +3Z+#nGtk
:KS"&h{SY
z=Xh
InputStream input = httpConnection.getInputStream(); }yw>d\] f
//logResponseHead(httpConnection); _%(.OR
*0'< DnGW
3 6t^iV*3
byte[] b = new byte[1024]; B_>r|^Vh
int nRead; `W.g1"o8W4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ua,!kyS
{ zF(abQ0
nStartPos += fileAccessI.write(b,0,nRead); Y++n0sK5<
//if(nThreadID == 1) . Ctd$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h=^UMat-
} |-z"6F r-
,\N4tG1\
MHJRBn{}
Utility.log("Thread " + nThreadID + " is over!"); O+]'*~a
bDownOver = true; 1C0' Gf)3
//nPos = fileAccessI.write (b,0,nRead); V!NRBXg
} wLNkXC
catch(Exception e){e.printStackTrace ();} ?} lqu7S
} L nyow}
} Vq'n$k}
h.kjJF
U5p3b;
//打印回应的头信息 p!DOc8a.\e
public void logResponseHead(HttpURLConnection con) <r m)c.
{ y{2\T
for(int i=1;;i++) &"7+k5O
{ zL9:e7o
String header=con.getHeaderFieldKey(i); PbFbihg
if(header!=null) Q7\j:.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); T8d=@8g,%
Utility.log(header+" : "+con.getHeaderField(header)); Dw$RHogb~y
else N:~4>p44[
break; '*^9'=
} "Y@q?ey[1
} ).-#
1 hD(l6tG@
gw^W6v
public void splitterStop() Q\N >W+d
{ 2#N?WlYw<S
bStop = true; &MPlSIg
} E<7$!P=z`
9Ais)Wy%p
!M(SEIc4A
} !Y&]Y G
ct<XKqbI
m#4h5_N
/* 2*a9mi
**FileAccess.java 3*\hGt,ZP
*//文件访问(定位，写) 8dCRSU
package NetFox; NE4]i
import java.io.*; #^(Yw|/K
6cD3(//
uc}F|O
public class FileAccessI implements Serializable{ #g'j0N
zGy+jeH:.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <p-@XzyE
RandomAccessFile oSavedFile; :jC$$oC].
long nPos; A[F_x*S
mF UsTb]f
YMVi7D~;Q$
public FileAccessI() throws IOException D1@yW} 4
{ |<O^M q
this("",0); F{rC{5@fj
} W|"bV 6d3
uGHM ]"!)
v=Q!ioE7
public FileAccessI(String sName,long nPos) throws IOException 2p4iir
{ -*OL+
oSavedFile = new RandomAccessFile(sName,"rw"); 1hzf+*g
this.nPos = nPos; U@D\+T0
oSavedFile.seek(nPos); Spin]V
} C](djkA$
2cSc 8
B I=57
public synchronized int write(byte[] b,int nStart,int nLen) !;P[Y"h@r
{ 0d1!Q!PH3
int n = -1; S!b?pl
try{ p.b#RY
oSavedFile.write(b,nStart,nLen); 2 /*z5
n = nLen; H!Dj.]T
} 'Gamb+[
catch(IOException e) $s-B
{ H328I}7
e.printStackTrace (); ivB,s5<
} ,~DKU*A_~
)u4=k(
-yb7s2o
return n; kD7'BP/#
} _18Z]XtX
5NhAb$q2Y
qq3/K9 #y
} lY2~{Y|4s
}E[vW
yu&muCA
/* IO]tO[P#
**SiteInfoBean.java Qwve-[
*/ j5A>aj
package NetFox; (44L8)I.D
)>U"WZ'<
#2$wI^O
public class SiteInfoBean { -$_FKny
J<4_<.o(a
ynZEJKo
private String sSiteURL; //Site's URL &9z&#`AY]>
private String sFilePath; //Saved File's Path eu~ u-}.
private String sFileName; //Saved File's Name ~%eE%5!k
private int nSplitter; //Count of Splited Downloading File O(v>\MV
B9$pG
[_(uz,'
public SiteInfoBean() BUV4L5(
{//nSplitter的缺省值为5 %4t?X
//default value of nSplitter is 5 NU+PG`Vb
this("","","",5); y>#kT
} X.FoX
~4O3~Y_+GN
hl] y):
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e@S$[,8
{ Sw$/Z)1K&
sSiteURL= sURL; Nl/ fvJ`4
sFilePath = sPath; H q?F@X
sFileName = sName; ?L H[,8z
this.nSplitter = nSpiltter; cfRUVe
^:mKTiA-
%M/L/_d
} <|]i3_Z
ld):Am}/o
EwgNd Gcj
public String getSSiteURL() Cbl>eKw
{ pGF;,h>
return sSiteURL; }_}
} bj0<A
Ciz,1IV
5w{U/v$Z
public void setSSiteURL(String value) (FZ8T39
{ ?<Hgq8J
sSiteURL = value; jC$~m#F
} O '`|(L
%++S;#)~
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public String getSFilePath() q8.Z7ux
{ 8 nqF i
return sFilePath; qJO6m-
} -dN`Ok<g
~l.C-
59v=\; UI
public void setSFilePath(String value) UV av^<_
{ (Q ^=^s|
sFilePath = value; w5rtYTI
} 6c27X/'Z
2PUB@B' +
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public String getSFileName() I9rQX9#B
{ O8N1gf;t
return sFileName; ~E_irzOFP
} c* ~0R?
xDSiTp=)O
qW|h"9sr
public void setSFileName(String value) ~X %cbFom=
{ 2']0c z
sFileName = value; m!!;CbPo
} 6 b?K-)kL
R/Sm
[u J<]
public int getNSplitter() [D(JEO@ :
{ V$;`#J$\b
return nSplitter; gp~-n7'~O
} O U9{Y9e
r2PN[cLu|
(2"4PU8
public void setNSplitter(int nCount) -*Qg^1]i+
{ 1=E}X5
nSplitter = nCount; (!0_s48f
} *UJB*r
} 45iO2W uur
n<HF]
yp@cn(:~
/* UfV {m
**Utility.java 9$VdYw7D
*/ 7lJ8<EP9 u
package NetFox; V~5vR`}
uC#]F@
p)"EenUK
public class Utility { JHVndK4L
+iQ~ Y2Gh
IM[=]j.?
public Utility() wN6sica|
{ rq1~%S
EG8z&^O x
vl|3WYA
} z~v-8aw
k<f0moxs'
//线程睡眠 F8{T/YhZ
public static void sleep(int nSecond) 66+]D4(k
{ 9)j"|5H
try{ J4iu8_eH!D
Thread.sleep(nSecond); <Nc9F['&#
} *laFG<;
catch(Exception e) 3O2vY1Y2
{ QV*la=j/
e.printStackTrace (); 0TICv2l!
} VeQ [A?pER
} 1hV&/Qr
/w2IL7}
//日志 x}d5Y
public static void log(String sMsg) $[J\sokpY
{ je>gT`8
System.err.println(sMsg); @wP.Rd
} _n4`mL8>kH
ZX{eggXl
P/]8+_K
public static void log(int sMsg) BCd0X. m(
{ V2tA!II-s
System.err.println(sMsg); p!?7;
} r.:f.AY{
} q?L*Luu+
wJvk
G`;mSq6i
/* cRf;7G
**TestMethod.java ~Sd,Tu%:
*/ 5VfpeA`
package NetFox; y4!fu<[i
o5Knot)Oy
[r'hX#
public class TestMethod { +s [_ 4
soKR*gJ,
a{?>F&vnU
public TestMethod() o+R(ux"
{ ///xx/weblogic60b2_win.exe I4c%>R
try{ )_kEy>YscZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4L,&a+)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b~8&P_
SiteFileFetch fileFetch = new SiteFileFetch(bean); CyB1`&G>
fileFetch.start(); U[#q"'P|l
} $.B}zY{
catch(Exception e){e.printStackTrace ();} ~ r$I&8
_qQo}|/q
:n x;~f
} u/\Ipk/
otP2qAI
)S_%Ip
public static void main(String[] args) )MX%DQw
{ %U1HvmyK
new TestMethod(); 0nlh0u8#
} z:{R4#(Q
} tfe'].uT
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