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)); R.jIl@p
} sF!($k;!
for(int i=0;i<nEndPos.length-1;i++) G_;)a]v8)
{ Sj]T
nEndPos = nStartPos[i+1]; GPkmf%FJ
} 2D75:@JL}|
nEndPos[nEndPos.length-1] = nFileLength; qkt0**\
} QLXN*c
} m+`fn;*
w~(1%p/
.L9j>iP9 *
//启动子线程 mg^I=kpk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~zHjMo2
for(int i=0;i<nStartPos.length;i++) S^-DK~Xt4
{ 0Vlk;fIh
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aC$B2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aZ2!i
nStartPos,nEndPos,i); ]NUl9t*N4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JlH&??
fileSplitterFetch.start(); K(q+ "
} ]$ L|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'n{Nvt.c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +c(zo4nZ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^T*?>%`
nEndPos = " + nFileLength); ![`Ay4AZ@a
// fileSplitterFetch[nPos.length-1].start(); u[@l~gwL
Eo{"9j\
3.|S
//等待子线程结束 F~T]u2qt
//int count = 0; }Mstjm
//是否结束while循环 S{]x
boolean breakWhile = false; SX<` {x&L
iP =V8g?L
+MR.>"
while(!bStop) 8$")%_1]
{ *,e:]!*
write_nPos(); ]JCvyz H
Utility.sleep(500); -=%@L&y1
breakWhile = true; QqFR\6
(\\eo
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for(int i=0;i<nStartPos.length;i++) {_7i8c<s=
{ oC<.=2]
if(!fileSplitterFetch.bDownOver) g<l1zo`_
{ JSkLEa~<
breakWhile = false; S)cLW~=z
break; I9/W;# *~
} J2::'Hw*s
} v4u5yy_;(
if(breakWhile) NG--6\
break; 2;zb\d
hlV=qfc
igkYX!0#8O
//count++; 1Yq?X:
//if(count>4) Gr7=:+0n|P
// siteStop(); tX5"UQA
} g l^<Q
cv?06x{
q1z"-~i)E
System.err.println("文件下载结束！"); n!NS(.o
} tXoWwQD;Y
catch(Exception e){e.printStackTrace ();} k[bD\'
} @JtM5qB
JW{rA6?
q)Lu_6 mg
//获得文件长度 3Ndq>
public long getFileSize() 8cU}I4|
{ y+X2Pl
int nFileLength = -1; M.x=<:upp
try{ [0(B>a3J
URL url = new URL(siteInfoBean.getSSiteURL()); N/Z2hn/m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); % W=b?:
httpConnection.setRequestProperty("User-Agent","NetFox"); `);AW(Q
Xnz3p"
GNgKo]u
int responseCode=httpConnection.getResponseCode(); W?qmp|YD
if(responseCode>=400) 4.Q} 1%ZN
{ a2dnbfSWa[
processErrorCode(responseCode); OjFLPGRCh
return -2; //-2 represent access is error =8t]\Y?
} &:/hrighH
TV<'8L
=7w\ 7-.m
String sHeader; 9Xj7~,
_kj wFq
ur3(HL
for(int i=1;;i++) S4'
{ T;L>;E>B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !zkZQ2{Wn
//Utility.log(in.readLine()); u -;_y='m
sHeader=httpConnection.getHeaderFieldKey(i); d*jMZ%@uS
if(sHeader!=null) wj,:"ESb4
{ 87BHq)
if(sHeader.equals("Content-Length")) tZ'|DCT
{ 6{"$nF]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v:!Z=I}>
break; |_] Q$q[[%
} ePr&!Tz#
} 2^y^q2(r
else <}E!w_yi
break; pnjXf.g"O
} 4(|cG7>9-
} ba[1wFmcL
catch(IOException e){e.printStackTrace ();} qHuZcht
catch(Exception e){e.printStackTrace ();} v-#Q7T
#pb92kA'
e4!:c^?
Utility.log(nFileLength); X'd9[).
)\eI;8
%+j8["VEC
return nFileLength; LW[9
} m;'6MHx;
()5[x.xK@
X;i~<Tq
//保存下载信息（文件指针位置） EH256f(&
private void write_nPos() gu0j.XS^
{ TM_/`a2}
try{ >+JqA7K
output = new DataOutputStream(new FileOutputStream(tmpFile)); v3aYc:C
output.writeInt(nStartPos.length); }q $5ig
for(int i=0;i<nStartPos.length;i++) y0#u9t"Z;
{ oXb;w@:
// output.writeLong(nPos); N>XS=2tzN
output.writeLong(fileSplitterFetch.nStartPos); $})g?Q
output.writeLong(fileSplitterFetch.nEndPos); P!H_1RwXKC
} *1v[kWa?
output.close(); Y"~gw~7OD
} ^lA=* jY(
catch(IOException e){e.printStackTrace ();} ~F4fFQ-yy
catch(Exception e){e.printStackTrace ();} E~]R2!9
} qAn!RkA
pi Z[Y 5OE
OW3sS+y
//读取保存的下载信息（文件指针位置） w2 a1mU/
private void read_nPos() >4#)r8;dx
{ Y0x%sz5
try{ 5Ow[~p"l<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `8AR_7i
int nCount = input.readInt(); hp#W9@NR
nStartPos = new long[nCount]; %k;|\%B`
nEndPos = new long[nCount]; (Tn- >).AO
for(int i=0;i<nStartPos.length;i++) 0w)^)
{ l:j4Ft 8
nStartPos = input.readLong(); |N%fMPKa
nEndPos = input.readLong(); hWD;jR
} IFF92VD&
input.close(); Hea;?4Vg
} g/P+ZXJ
catch(IOException e){e.printStackTrace ();} -(
catch(Exception e){e.printStackTrace ();} bYEy<7)x
} ,1[q^-9
'}fzX2Q#
NYrQ$N"
private void processErrorCode(int nErrorCode) v6>_ j L
{ {ys=Ndo8
System.err.println("Error Code : " + nErrorCode); {u#;?u=|
} =<?+#-;p
-Z 4e.ay5
/ c AUl
//停止文件下载 DNr@u/>vB
public void siteStop() M luVx'
{ GBRa.;Kk
bStop = true; /atW8 `&
for(int i=0;i<nStartPos.length;i++) Q36qIq_0e
fileSplitterFetch.splitterStop(); V:VO[e<e
~GL]wF2#
G LIi6
} aqj@Cjk4Z
} ,.OERw
//负责部分文件的抓取 (NF~Ck$#q
**FileSplitterFetch.java @GdbTd
*/ ";3zXk[#
package NetFox; vUohtS*
3NqN\5B:
dwDcR,z?a
import java.io.*; u*Pibgd<
import java.net.*; P_*" dza
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X!9 B2w
public class FileSplitterFetch extends Thread { #,":vr
*7ZN]/VRT
>zXsNeGQR
String sURL; //File URL &6ZD136
long nStartPos; //File Snippet Start Position e[&L9U6GW-
long nEndPos; //File Snippet End Position KG|n
int nThreadID; //Thread's ID LR".pH13
boolean bDownOver = false; //Downing is over nV-mPyfL8
boolean bStop = false; //Stop identical ^,/RO5
FileAccessI fileAccessI = null; //File Access interface (Iaf?J5{
`$W_R[
(9Ux{@$o[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _j< K=){
{ G 8g<>d{j
this.sURL = sURL; l'/R&`-n
this.nStartPos = nStart; B9NWW6S
this.nEndPos = nEnd; 19E8'@
nThreadID = id; inh=WUEW
fileAccessI = new FileAccessI(sName,nStartPos);//定位 apg=-^L'
} |mGFts}0o'
, udTvI
}bdmomV
public void run() W-?()dX{
{ ]6TATPIr
while(nStartPos < nEndPos && !bStop) ms*(9l.hOK
{ _kU:Z
o<COm9)i
_'{_gei_P
try{ amOnqH-(
URL url = new URL(sURL); ]yK7PH-{L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BG6B:
httpConnection.setRequestProperty("User-Agent","NetFox"); eZIhEOF
String sProperty = "bytes="+nStartPos+"-"; AiEd!u.
httpConnection.setRequestProperty("RANGE",sProperty); ~Y|*`C_)
Utility.log(sProperty); GP?M!C,/}k
DU5c=rxW
BJM.iXU)[
InputStream input = httpConnection.getInputStream(); `*_mP<Ag
//logResponseHead(httpConnection); C8Qa$._
2+QYhdw
S|7!{}
byte[] b = new byte[1024]; WvBc#s-
int nRead; zNxW'?0Z?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c:<005\Bg
{ kEOS{C%6R
nStartPos += fileAccessI.write(b,0,nRead); "B3N*R(["
//if(nThreadID == 1) JBE!j-F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mS(fgq6
} UNom-
r:f[mk"-"A
S- pV_Ff
Utility.log("Thread " + nThreadID + " is over!"); 9Uj$K>:
bDownOver = true; mz,
//nPos = fileAccessI.write (b,0,nRead); 3I)VHMC
} D~hg$XzK
catch(Exception e){e.printStackTrace ();} ="Ho%*@6
} *AO,^R&e.
} 'EbWFMjy
3RYpJAH
u%}nw :>
//打印回应的头信息 e1%/26\
public void logResponseHead(HttpURLConnection con) fGUE<l
{ >O*IQ[r-
for(int i=1;;i++) CE#gfP
{ F`gi_;c
String header=con.getHeaderFieldKey(i); VH9dleZ
if(header!=null) /{+y2.{j
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mRL"nC
Utility.log(header+" : "+con.getHeaderField(header)); "D63I|O)
else +jS|2d
break; CG0 M
} !W5 (
} qU%/W|LY
r^FhTzA=1
=Xi07_8Ic<
public void splitterStop() 3Dng1}
{ :~2vJzp@?
bStop = true; 2%LLSa
} "P7nNa
;<&*rnH
ar__ Pf6r
} JmxH"7hTE
9^oKtkoDZ
yXSFjcoB
/* =/s>Q l
**FileAccess.java s/$?^qtyC
*//文件访问(定位，写) qh9Z50E9
package NetFox; 8K:y\1
import java.io.*; lAb*fafQy
2oVSn"
:r{<zd>;
public class FileAccessI implements Serializable{ 8(pp2rlR
1S{D6#bE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J]{QB^?
RandomAccessFile oSavedFile; ]^h]t~
long nPos; ''yB5#^w(
r_ I5.gK
r[|Xy>Zj
public FileAccessI() throws IOException [@VP?74
{ ^E;kgED5
this("",0); U#lCj0iUt,
} A P)L:7w'e
Bt@^+vH ~
_zY#U9
public FileAccessI(String sName,long nPos) throws IOException &dqLP95
{ C _'%NlJ'
oSavedFile = new RandomAccessFile(sName,"rw"); .+PI}[g
this.nPos = nPos; u+Y\6~=+
oSavedFile.seek(nPos); %|auAq&w
} tr<Nm6!
Hx"ob_^'7
nV"~-On
public synchronized int write(byte[] b,int nStart,int nLen) e>6y%v;
{ dBYmiF!+
int n = -1; t<#TJ>Le
try{ th
oSavedFile.write(b,nStart,nLen); O#ai)e_uQk
n = nLen; ??^5;P{yx
} GWZ }7ake
catch(IOException e) `, OG7hg
{ @5N]ZQ9
e.printStackTrace (); smlpD3?va
} ;rF\kX&Jh
2;k*@k-t
h;p>o75O
return n; <c2E'U)X
} MI/MhkS ?
94h]~GqNi
fz|cnU
} IHB}`e|
XW[j!`nlk
7I&&bWB
/* s2h@~y
**SiteInfoBean.java J[l7di5
*/ qX/y5F`
package NetFox; (/=f6^}
MLXNZd
GZEc l'h*
public class SiteInfoBean { ?4+9fE<Q
} df W%{
V3&RJ k=b
private String sSiteURL; //Site's URL ]] !VK
private String sFilePath; //Saved File's Path ). <-X^@
private String sFileName; //Saved File's Name qraSRK5
private int nSplitter; //Count of Splited Downloading File gH$ Mr
_GV:HOBi
zNs55e.rx
public SiteInfoBean() xcd#&
{//nSplitter的缺省值为5 S=MEG+Ad
//default value of nSplitter is 5 X3{G:H0\p
this("","","",5); yQU{zY
} .CL[_;}
/NLui@|R
h{CL{>d
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =#;3Q~:Jl^
{ \K5DOM "#
sSiteURL= sURL; I4'5P}1yp
sFilePath = sPath; )F}F_Y
sFileName = sName; Lb!Fcf|h
this.nSplitter = nSpiltter; ?qP7Y nl
C_( *>!Z%
caU0\VS
} ynq}76 H0k
N@2dA*T,
>tYm+coS
public String getSSiteURL() ohRjvJ'v|
{ q3mJ782p]
return sSiteURL; v_BcTzQ0S
} r)lEofX,g+
8NxM4$nQX
B}n,b#,*
public void setSSiteURL(String value) L9r8BK;
{ J*r*X.
sSiteURL = value; -f3p U:G8
} ?iw!OoZ`
P0SQr?W
\MA+f~)9
public String getSFilePath() VQ(jpns5
{ gT3_RUF
return sFilePath; };mA^xO]j
} p#&h=,W}
E-4b[xNj*+
6hw=
public void setSFilePath(String value) |ax3sAg
{ Ghu#XJB?
sFilePath = value; h`]Iy
} A}BVep@D
_Us#\+]_:
m!gz3u]rN
public String getSFileName() ],>@";9u"
{ ?~l6K(*2
return sFileName; a+[RS]le
} HU1h8E$-
n3T>QgK
;%B(_c
public void setSFileName(String value) bk[U/9Z\
{ F5LuSy+v
sFileName = value; l>2E (Y|
} $~~Jw]
ls_'')yp
cL-[ZvyVX
public int getNSplitter() }QN1|mP2
{ JUsQ,ETn
return nSplitter; >NO[UX%yP
} D|lzGt
spGb!Y`mR
5 f@)z"j
public void setNSplitter(int nCount) ?L5zC+c!
{ pf2[,v/
nSplitter = nCount; b[sx_b
} J}*,HT*
} qaqBOHI6G
]S&&|Fc
i)o2klIkB
/* ."TxX.&HE
**Utility.java J &o|QG
*/ cW~}:;D4
package NetFox; }'5MK
!SC`D])l
bo,_&4?
public class Utility { szb_*)k
i#&z2h-b
.\\DKh%
public Utility() _mzW'~9wN
{ O#n8=B4
Htay-PB }
jk"`Z<j~
} 45=bGf#
r [9x
//线程睡眠 n#/_Nz
public static void sleep(int nSecond) rR$h*
{ mH54ja2
try{ 5 z~1Dw
Thread.sleep(nSecond); __lM7LFL
} ,oORW/0iS
catch(Exception e) d)B@x`
{ @*F"Q1 wI
e.printStackTrace (); b}OY4~ Y4
} ~9?cn
} Av @b!iw+
Y_Eb'*PY
//日志 &qLf@1AD
public static void log(String sMsg) 3T31kQv{
{ xqXo0
System.err.println(sMsg); \K_ET> !
} z(o,m3@v
AG3>V+k{Lv
9TU88]
public static void log(int sMsg) 1;d$#j
{ E_gD:PPU5
System.err.println(sMsg); t![7uU.W
} fs|)l$Rd
} 2{M^,=^>
VGLaN%|
!*/*8re
/* Nw:GCf-L
**TestMethod.java yTyj'-4
*/ &*sP/z
package NetFox; 68bQ;Dv
*xc_k"\
h~A/y!s
public class TestMethod { *zNYZ#
V @rI`~$
%`k6w3qI
public TestMethod() 9 ^o-EC!_
{ ///xx/weblogic60b2_win.exe VJ84?b{c W
try{ pb^i^tA+A
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m9)p-1y@5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6f;fx}y
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3yANv?$a
fileFetch.start(); -1Jg?cPzk
} +O'3|M
catch(Exception e){e.printStackTrace ();} gwNq x"
TH)"wNa
.=U#eHBdAQ
} Gk967pC
gep;{G}
g6nkZyw
public static void main(String[] args) K7$x<5+)
{ yZd +^QN
new TestMethod(); H!vax)%-\
} .R`5Qds*l
} |yvQ[U~PQ
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