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)); 0A$x'pU)
} k.UQT^.
for(int i=0;i<nEndPos.length-1;i++) >SS YYy
{ ZY NHVR
nEndPos = nStartPos[i+1]; p%MH**A
} b=Rw=K.
nEndPos[nEndPos.length-1] = nFileLength; u/W
} |/Q7 o1i
} CVo2?ZQ
II=(>G9v
vE4ce
//启动子线程 8cN[t.S
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; frsqnvm;+
for(int i=0;i<nStartPos.length;i++) mBb;:-5
{ Yfro^}f
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q:U^):~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w0`aW6t#
nStartPos,nEndPos,i); _T[7N|'O
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a g=,oYn
fileSplitterFetch.start(); G.ag$KF
} }V@ * :3w8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1^F !X=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); LI`L!6^l
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e15_$M;RW
nEndPos = " + nFileLength); .rfKItd
// fileSplitterFetch[nPos.length-1].start(); Z %?: CA
>b6!*Lrhs
m*'^*#
//等待子线程结束 "YW&,X5R
//int count = 0; `TugtzRU
//是否结束while循环 +@n8DM{b
boolean breakWhile = false; P;B<R"
>j&+mii
_tl
while(!bStop) 6I5,PB
{ ED0Vlw+1
write_nPos(); f=$w,^)M
Utility.sleep(500); $>Y2N5
breakWhile = true; l'Oz-p.@
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<oJM||ZA
for(int i=0;i<nStartPos.length;i++) 6R.%I{x'
{ l+%2kR
if(!fileSplitterFetch.bDownOver) 16;r+.FB'
{ n2e#rn
breakWhile = false; cM'\u~m{
break; V5]}b[X
} j=&]=0F
} 5"5tY
if(breakWhile) %3"xn!'vf
break; osBwX.G'l
\w;d4r8x
;F)j,Ywi)H
//count++; G&eRhif
//if(count>4) LIm{Y`XU
// siteStop(); >v sy P
} B~\mr{|u
8mrB_B5
Rw j4
System.err.println("文件下载结束！"); tWT,U[
} mgODJ
catch(Exception e){e.printStackTrace ();} SVJL|S3k
} O %x<
> T$M0&<
^(w%m#
//获得文件长度 Z4&,KrV
public long getFileSize() u ZzO$e
{ FR bmeq3c
int nFileLength = -1; pJnT \~o
try{ B^;G3+}
URL url = new URL(siteInfoBean.getSSiteURL()); "L?h@8sa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c8@zpkMj/
httpConnection.setRequestProperty("User-Agent","NetFox"); lKtA.{(
1KHFzx,
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int responseCode=httpConnection.getResponseCode(); .el&\Jt
if(responseCode>=400) ()Tl\
{ pm)kocG
processErrorCode(responseCode); Wqy\yS [
return -2; //-2 represent access is error =sp5.-r
} =hw&2c
#![9QUvcf
eNQQ`ll@m
String sHeader; t\GoUeH]
[WfigqY`b*
H}ie D"T_
for(int i=1;;i++) %oee x1`=
{ yF [|dB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); z(o zMH
//Utility.log(in.readLine()); t9QnEP'
sHeader=httpConnection.getHeaderFieldKey(i); fV "gL(7
if(sHeader!=null) ' F,.y6QU
{ KxA^?,t[
if(sHeader.equals("Content-Length")) 5 R*
{ >'/KOK"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o(gEyK
break; nq/SGo[c
} s%6{X48vY^
} D ,U#z
else , z-#B]
break; 9"g!J|+
} 6_&uYA<8pE
} VB}4#-dG?
catch(IOException e){e.printStackTrace ();} t7P[^f15[
catch(Exception e){e.printStackTrace ();} @P'("qb~
&E/0jxM1
_nn\O3TB
Utility.log(nFileLength); ?z[k.l+6w
s7789pR
*XCgl*% *
return nFileLength; h1_9Xp~N
} 8kRqF?rbj
|/YwMBi
"p"M9P'
//保存下载信息（文件指针位置） e`7dRnx&0
private void write_nPos() *WQl#JAr
{ K/;*.u`:
try{ MEI.wJZ
output = new DataOutputStream(new FileOutputStream(tmpFile)); ##\ <mFE
output.writeInt(nStartPos.length); Xc}~_.]
for(int i=0;i<nStartPos.length;i++) ((AsZ$[S
{ =O.%)|
// output.writeLong(nPos); H\PY\O&cP
output.writeLong(fileSplitterFetch.nStartPos); m4m,-}KNi
output.writeLong(fileSplitterFetch.nEndPos); J ,s9,("
} iVUkM3
output.close(); &{R]v/{p]
} SK]"JSY`
catch(IOException e){e.printStackTrace ();} s(?A=JJ
catch(Exception e){e.printStackTrace ();} 4nz$Ja)
} v PJ=~*P=
1y{@fg~..
R'z -#*[
//读取保存的下载信息（文件指针位置） ir?Y>
private void read_nPos() K^yZfpa8
{ bCSgdK
try{ &F 3'tf?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +lNAog
int nCount = input.readInt(); "J=A(w5
nStartPos = new long[nCount]; X }""= S<
nEndPos = new long[nCount]; wvnuE<o8
for(int i=0;i<nStartPos.length;i++) CKuf'h#
{ 37U2Tb!y'
nStartPos = input.readLong(); LP{@r ic
nEndPos = input.readLong(); gP^p7aYwn
} .S6u{B
input.close(); |bM?Q$>~
} Cvgk67C=$
catch(IOException e){e.printStackTrace ();} .B?J@,
catch(Exception e){e.printStackTrace ();} ~USU\dni
} qrLE1b 1$
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r.vezsH
private void processErrorCode(int nErrorCode) *ak"}s
{ @&F\M}
System.err.println("Error Code : " + nErrorCode); T!ik"YZ@i
} a{y"vVQOF
0{k*SCN#
~]l T>|X
//停止文件下载 C%ZSsp u
public void siteStop() |EpL~G_
{ V.?Oly
bStop = true; m`lxQik
for(int i=0;i<nStartPos.length;i++) &f"kWOe$X
fileSplitterFetch.splitterStop(); rP<S =eb
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CW . O"_
} rv26vnJy"
} Y)](jU%o
//负责部分文件的抓取 wQR0R~|M
**FileSplitterFetch.java Z{p62|+Ck@
*/ {{+woL'C
package NetFox; iqAME%m
AZ'"Ua
VYAz0H1-_
import java.io.*; QZO9CLX 8k
import java.net.*; 92pl#Igt
qCUn. mI
F8En)#
public class FileSplitterFetch extends Thread { rd0[(-
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String sURL; //File URL sR*.i?lN
long nStartPos; //File Snippet Start Position H]a@"gO
long nEndPos; //File Snippet End Position rD*CLqK
int nThreadID; //Thread's ID /)LI1\o
boolean bDownOver = false; //Downing is over 1cvH
boolean bStop = false; //Stop identical T0F!0O `
FileAccessI fileAccessI = null; //File Access interface !Bqmw
E#^?M#C
w.0:#4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >6\rhx>
{ 7w8I6
this.sURL = sURL; 5.o{A#/NTl
this.nStartPos = nStart; A{(<#yRfg
this.nEndPos = nEnd; *0!IHr"fn
nThreadID = id; ,EuJ0]2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 SBog7An9SI
} 4.o[:5'
#CcWsI>+w>
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public void run() k,M%"FLQ
{ =3R5m>6!/
while(nStartPos < nEndPos && !bStop) f!D~aJ
{ tI;pdR]
|`c=`xK7'
qFwJ%(IQ
try{ r[votdFo
URL url = new URL(sURL); 5:6]ZFW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @,%IVKg\
httpConnection.setRequestProperty("User-Agent","NetFox"); - )brq3L
String sProperty = "bytes="+nStartPos+"-"; o9 g0fC
httpConnection.setRequestProperty("RANGE",sProperty); |-! yKB
Utility.log(sProperty); idLCq^jnJ
*5Aq\g,n
rZSX fgfr
InputStream input = httpConnection.getInputStream(); -)dS`hM
//logResponseHead(httpConnection); Lr;PESV
lMW4SRk1C
yw{;Qm2\7
byte[] b = new byte[1024]; 8Ug`2xS<_
int nRead; +i1\],7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _=d X01
{ 0s+pcqOd^
nStartPos += fileAccessI.write(b,0,nRead); I6B4S"Q5<
//if(nThreadID == 1) Rb=8(#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MRZ/%OZ.
} *]]C.t-cd
du0]LiHV
:Tu%0="ye
Utility.log("Thread " + nThreadID + " is over!"); r1o_i;rg
bDownOver = true; I,0Z* rw
//nPos = fileAccessI.write (b,0,nRead); V/@?KC0B5
} ,U?W
catch(Exception e){e.printStackTrace ();} :!nBTw
} QZ:xG:qyk;
} hJIF!eoI
u{>_Pb
wO&2S-;_K
//打印回应的头信息 !v`C-1}70
public void logResponseHead(HttpURLConnection con) Zv8I`/4?
{ TP-<Lhy
for(int i=1;;i++) H.R7,'9
{ 2B<0|EGtzw
String header=con.getHeaderFieldKey(i); ' +*,|;?
if(header!=null) (bBr O74lR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); KWzJ
Utility.log(header+" : "+con.getHeaderField(header)); Z.v2!u
else ~3F\7%Iqc
break; 7\e96+j|f
} pS C5$a(
} C6P(86?
|4tnG&=
LG6k KG
public void splitterStop() g3"eEg5NY
{ w\PCBY=
bStop = true; #vnJJ#uI|>
} lAcXi$pF
""2g{!~r
fL7u419=
} =O?#>3A}
sHwn,4|iY
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/* oy?>e1Sy*
**FileAccess.java )rP)-op|A
*//文件访问(定位，写) FJj#
package NetFox; $F,&7{^
import java.io.*; mhXSbo9w-
AT6:&5_`
u|'}a3
public class FileAccessI implements Serializable{ vKCgtk
!R/-|Kjy
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 lxvRF93a.
RandomAccessFile oSavedFile; $4j$c|S!
long nPos; 5?()o}VjAO
3{;W!/&>
Es~|:$(N]|
public FileAccessI() throws IOException `T \"B%
{ !Ui"<0[,
this("",0); %j*i=
} )f6:{ma
<m|\#Jw_V
W18I"lHeh
public FileAccessI(String sName,long nPos) throws IOException ,& ^vc_}
{ xO<$xx
oSavedFile = new RandomAccessFile(sName,"rw"); (3;dtp>Xx
this.nPos = nPos; .}V&*-ep
oSavedFile.seek(nPos); ,%a7sk<5k
} mGK-&|gq
5v uB87`
qXQ/M]
public synchronized int write(byte[] b,int nStart,int nLen) mm5y'=#
{ @/m|T]'8
int n = -1; U=G^wL
try{ H"g$qSx
oSavedFile.write(b,nStart,nLen); <e:2DB&
n = nLen; KfVLb4@16_
} S_B $-H|
catch(IOException e) {#c**' 4
{ UI,i2<&
e.printStackTrace (); *Ugtg9j
} 22<T.c
u?>]C6$
v\UwL-4[
return n; {_]'EK/w
} 5"]t{-PD
jr9/
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} -a}d @&
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gtBnP~zT\B
/* 8] BOq:
**SiteInfoBean.java 71h?t`N
*/ N{(Q,+ ~
package NetFox; f~3_Rv!
CX8tTbuFl
~ }<!ON;
public class SiteInfoBean { ^.d97rSm
nsCat($)
;BR`}~m
private String sSiteURL; //Site's URL sPee"9%,
private String sFilePath; //Saved File's Path }5)sS}C
private String sFileName; //Saved File's Name SgOn:xg;3L
private int nSplitter; //Count of Splited Downloading File o~*5FN}%+l
'Si1r%'m#
'<v/Gl\
public SiteInfoBean() c QjzI#
{//nSplitter的缺省值为5 BK_x5mGu3
//default value of nSplitter is 5 +Y^_1
this("","","",5); (v\Cv)OS
} B`/cKfg
a09]5>*
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c 4<~?L
{ K`9ph"(Z
sSiteURL= sURL; oM@X)6P_
sFilePath = sPath; _l`s}yC
sFileName = sName; W|PKcZ ]Uc
this.nSplitter = nSpiltter; "o*zZ;>^
3KF[ v{
^}-(8~_en
} 6tE<`"P!
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ZjE!? '(ef
public String getSSiteURL() 88dq8T4
{ amL8yb
return sSiteURL; rSYzrVc
} ?\QEK
~ "]6
8%UI<I,
public void setSSiteURL(String value) ]Y3|*t(\
{ n%Vt r
sSiteURL = value; qq&G~y
} rf%E+bh4
,Z7tpFC
'~^3 =[Z
public String getSFilePath() dnby&-+T
{ g2=5IU<
return sFilePath; LDJ=<c!
} fR>(b?C
ldJ:A*/M6
rKDMIECrm
public void setSFilePath(String value) 2Et7o/\<
{ k-LB %\p
sFilePath = value; Tm8c:S^uq)
} !!=%ty
):. +u=
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public String getSFileName() qp-/S^%
{ #-9;Hn4x
return sFileName; C^@~
} R~,*W1G6sF
"RG.27
C(:tFuacpw
public void setSFileName(String value) hCX}*
{ CW(]6s u{
sFileName = value; xud
} Y 9eGDpW
{]\QUXH
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public int getNSplitter() BfLh%XC
{ qY24Y
return nSplitter; I9ga8mG4-'
} XD5z+/F<"0
lE+v@Kb:
6#+&_#9
public void setNSplitter(int nCount) Tc6H%itV
{ PrIS L[@
nSplitter = nCount; !b"#`O%`
} E%M~:JuKd?
} cH()Ze-B
yfS`g-j{~
jXO*_R
/* -WIT0F4o;
**Utility.java M"OXNPkc
*/ {89F*
package NetFox; jUq^$+N
/@5X0m
#c5 NFU}9
public class Utility { C3af>L@}
klG]PUzd
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public Utility() .c'EXuI7),
{ @0q%&v0
Ed3 *fY
bz[+g,e2oA
} +Io[o6*
NTk"W!<Cl2
//线程睡眠 YCwfrz
public static void sleep(int nSecond) $X~4J
{ +I0?D
try{ -r_/b
Thread.sleep(nSecond); &eQF[8 ,
} B Mh949;
catch(Exception e) uhUC m
{ lHwQ'/r
e.printStackTrace (); e,qc7BJzK
} @ oE [!
} 9l?#ZuGXp
O $uXQ.r
//日志 B:=*lU.n
public static void log(String sMsg) ~A+DH
{ 0+b1R}!2
System.err.println(sMsg); sm-RpZ&|
} "Y9 *rL
Exox&T
'vT XR_D
public static void log(int sMsg) &ZgB b
{ 2{zFO3i<3
System.err.println(sMsg); |q5R5mQ
} h_4o4#
} <">tB"="b
N^A&DrMF
/#M|)V*wn
/* *P&ZE
**TestMethod.java Hq h
*/ *p{wC r
package NetFox; GMLq3_'
-E#!`~&V
O0#wM-M
public class TestMethod { DG&14c>g
R=~+-^O!
U]lXw+&
public TestMethod() DQ^yqBVgQ
{ ///xx/weblogic60b2_win.exe oJy]n9
try{ [^B04x@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _ 97
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w?A&XB+
SiteFileFetch fileFetch = new SiteFileFetch(bean); yzt6
fileFetch.start(); |D u.aN
} RQ#gn
catch(Exception e){e.printStackTrace ();} PZ~uHX_d>
A,rgN;5fb
2-i>ymoOS
} b(dIl)Y4 :
uYAPGs#k
O:3pp8
public static void main(String[] args) Y9ueE+6
{ LD5n_W
new TestMethod(); LUv>0G#L[
} #L.fGTb
} %zQME6WELz
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