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)); kpT>xS^6<
} _}8hEv
for(int i=0;i<nEndPos.length-1;i++) GQ=Zp3[
{ OCR`1
nEndPos = nStartPos[i+1]; ~<[$.8*
} }G8gk"st
nEndPos[nEndPos.length-1] = nFileLength; z4GcS/3K
} y.h2hv]Bc
} 7.V'T=@x3)
6/u]r
)-yJKmV
//启动子线程 9g%1^$R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *4]u?R
for(int i=0;i<nStartPos.length;i++) KZ8Hp=s
{ kD_Ac{{<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y#aL]LxZE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }_,\yC9F
nStartPos,nEndPos,i); T!-*;yu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +qN}oyL
fileSplitterFetch.start(); |"}F cS y
} Vf28R,~m
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MR")
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0PfjD
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B49: R>
nEndPos = " + nFileLength); 0j{Rsy
// fileSplitterFetch[nPos.length-1].start(); =K#5I<x
Ka\ha
(<bYoWrK#
//等待子线程结束 v)+E!"R3.
//int count = 0; jh7-Fl`
//是否结束while循环 I8ZBs0sfF{
boolean breakWhile = false; zG IxmJ.
1f3c3PJ
[)efh9P*
while(!bStop) S($8_u$U
{ Oy(fh%k#
write_nPos(); <Zb~tYp
Utility.sleep(500); pl#2JA8
breakWhile = true; !{u`}:\
l\f /(&,
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for(int i=0;i<nStartPos.length;i++) \mK;BWg)
{ aMU0BS"
if(!fileSplitterFetch.bDownOver) Gm`#0)VC
{ B/Jz$D
breakWhile = false; h7r*5E
break; 0^lCZ,uq;
} 38<Z=#S
} DxM$4
if(breakWhile) KM-d8^\:
break; 1>~bzXY#
0H9UM*O
G4&vrM,f
//count++; pL [JGn
//if(count>4) \&!qw[;O
// siteStop(); =1MVF
} e]9Z]a2
P/!W']OO
\ 8v^ hb
System.err.println("文件下载结束！"); qV$\E=%fhM
} [SKN}:D
catch(Exception e){e.printStackTrace ();} 0Dt-!Q7
} Ji#eA[
PTS dW~3
gZf8/Tp\z
//获得文件长度 @PL.7FM<v
public long getFileSize() " ""k}M2A
{ #Sc9&DfX
int nFileLength = -1; 634OH*6
try{ -P6Z[V%
URL url = new URL(siteInfoBean.getSSiteURL()); -~_[2u^3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [r#m +R"N
httpConnection.setRequestProperty("User-Agent","NetFox"); TSKT6_IJw
-I0J-~#
v\Y8+dD
int responseCode=httpConnection.getResponseCode(); N^Hj%5
if(responseCode>=400) #c%FpR4
{ :L+%5Jq
processErrorCode(responseCode); |Cm6RH$(
return -2; //-2 represent access is error ?hmuAgOtbh
} ;Yve m
vojXo|c
`s8o2"12
String sHeader; %,UTFuM`
@ogj -ol&
d-cW47
for(int i=1;;i++) @|PUet_pb
{ Y@y"bjK \
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h!mx/Hx
//Utility.log(in.readLine()); 5W!#,jz
sHeader=httpConnection.getHeaderFieldKey(i); &_$0lIDQ
if(sHeader!=null) XW.k%H4@
{ ipe8U1Sc
if(sHeader.equals("Content-Length")) KvH t`
{ -#Ys67,4N
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XI+GWNAmJ
break; d:Oo5t)MN
} /# d^
} K(,MtY*
else z2lT4SAv+
break; 34,'smHi%
} RT. %\)))
} M%YxhuT0
catch(IOException e){e.printStackTrace ();} j#jwK(:]
catch(Exception e){e.printStackTrace ();} L0)w~F ?m
x=03WQ8
Z<iK(?@O
Utility.log(nFileLength); $|tk?Sps
skYHPwJdW
)UtK9;@"
return nFileLength; R; ui 4wg6
} T/PmT:Qg`
{DD #&B
Pm]lr|Q{I
//保存下载信息（文件指针位置） ..R JHa6B
private void write_nPos() CofTTYl
{ Qv<p$Up6
try{ 8,IQ6Or|-2
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1k]L,CX
output.writeInt(nStartPos.length); KF6N P
for(int i=0;i<nStartPos.length;i++) &Oc `|r*
{ `GSl}A
// output.writeLong(nPos); 5,pEJ>dDD3
output.writeLong(fileSplitterFetch.nStartPos); r PTfwhs
output.writeLong(fileSplitterFetch.nEndPos); <iBn-EG l>
} ^u2x26].
output.close(); / */"gz%
} }qJ`nN8
catch(IOException e){e.printStackTrace ();} /BN=Kl]
catch(Exception e){e.printStackTrace ();} }G "EdhSl
} icQQLSU5
($Op*bR
$DaQM'-
//读取保存的下载信息（文件指针位置） :r2d%:h%2
private void read_nPos() }KYOde@
{ voFg6zoV_
try{ kxR!hA8wv4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JAM]neKiX
int nCount = input.readInt(); dOK]Su
nStartPos = new long[nCount]; )%b 5uZ
nEndPos = new long[nCount]; Vry*=X&Q
for(int i=0;i<nStartPos.length;i++) 2r!- zEV
{ qnb/zr)p
nStartPos = input.readLong(); hE E1i
nEndPos = input.readLong(); +^jm_+
} J7sH]
input.close(); (Y*9[hm
} -Mf-8zw8G
catch(IOException e){e.printStackTrace ();} w5yX~8UzJ
catch(Exception e){e.printStackTrace ();} 0|]d^bo
} ">M&/}4
3ZN\F
Fn0|v66
private void processErrorCode(int nErrorCode) Ct^=j@g
{ N{}8Zh4op
System.err.println("Error Code : " + nErrorCode); V(XZ7<& {
} >l #D9%
>5E1y!
0_AIKJrL
//停止文件下载 {>PEl;,-
public void siteStop() LqO=wK~
{ cml~Oepf
bStop = true; aI=Q_}8-
for(int i=0;i<nStartPos.length;i++) DAg*
fileSplitterFetch.splitterStop(); ,)N/2M\B-
'? -N
`A5n6*A7
} acar-11_o/
} .S1MxZhbP
//负责部分文件的抓取 ]jPP]Z:y
**FileSplitterFetch.java Q/]o'_[vW
*/ <o[3*59
package NetFox; e2BC2K0
}#;.b'`
FhPCFmmUT
import java.io.*; z,hBtq:-$
import java.net.*; 2s>BNWTU
v,8Q9<=O
T@`Al('
public class FileSplitterFetch extends Thread { y<wd~!>Ubu
-/0aGqY
^16zZ*
String sURL; //File URL h@'CmIZc
long nStartPos; //File Snippet Start Position X$@qs9?)^
long nEndPos; //File Snippet End Position !! )W`
int nThreadID; //Thread's ID _~D#?cFY6
boolean bDownOver = false; //Downing is over Zy.ls&<:
boolean bStop = false; //Stop identical C@\5%~tW+
FileAccessI fileAccessI = null; //File Access interface s[dIWYs#
fBh/$
@|sBnerE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,!LY:pMK
{ U* c'xoP
this.sURL = sURL; Fq!_VF^r
this.nStartPos = nStart; C(h Td%
this.nEndPos = nEnd; H3`.Y$z
nThreadID = id; ~'0ZW<X.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )n1[#x^I
} *9w-eK1{
r{84Y!k~*
q_ryW$/_
public void run() c`UFNNm=
{ 5W&L cBB
while(nStartPos < nEndPos && !bStop) z]C=nXbk
{ 3:8p="$F
'-J<ib t
r:g_mMvB
try{ '?Q"[e
URL url = new URL(sURL); &['x+vL9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~iQBgd@D^
httpConnection.setRequestProperty("User-Agent","NetFox"); ](8F]J ,
String sProperty = "bytes="+nStartPos+"-"; 1|!)*!hu
httpConnection.setRequestProperty("RANGE",sProperty); %l#X6jkt
Utility.log(sProperty); T9!NuKfur
om9'A=ZU
e=s85!
InputStream input = httpConnection.getInputStream(); c#`IF6qj
//logResponseHead(httpConnection); dFhyT.Y?
vF pKkS343
7jQVm{{.
byte[] b = new byte[1024]; wHQ$xO;vD'
int nRead; =au!rda
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6Z'K1
{ I{WP:]"Yf
nStartPos += fileAccessI.write(b,0,nRead); bd-iog(
//if(nThreadID == 1) l?rLadvc
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |5:2?S2R
} o1?-+P/
}p)Hw2
>SLmlK
Utility.log("Thread " + nThreadID + " is over!"); NP.i,H
bDownOver = true; C984Ee
//nPos = fileAccessI.write (b,0,nRead); W[a"&,okqO
} '6e4rn{
catch(Exception e){e.printStackTrace ();} )G?\{n-
} 98O]tL+k/u
} GCiG50Z=
u*W! !(P/
zJl;|E".
//打印回应的头信息 *]h"J]
public void logResponseHead(HttpURLConnection con) 2<p@G#(
{ Eu"8IM!%-
for(int i=1;;i++) =<m!%/I
{ QxxPImubB
String header=con.getHeaderFieldKey(i); ?6nB=B)/
if(header!=null) QT73=>^B
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =Ry8E2NuM
Utility.log(header+" : "+con.getHeaderField(header)); Fj2z$
else cQ1Axs TO
break; -$:*!55:j
} ;Ss!OFK
} /\uopa
jAue+tB
)!cucY
public void splitterStop() x3#:C=
{ p~=z)7%e'
bStop = true; ov H'_'
} 7CSz
:@"o.8p
Hm!"%
} ;~djbo0,X
Uf]$I`T#
<H-kR\HF
/* MMC$c=4"
**FileAccess.java QA;,/iw`
*//文件访问(定位，写) S5, u| H
package NetFox; ebNRZJ?C,
import java.io.*; m[Ihte->
0*tnJB
|4P8N{ L>O
public class FileAccessI implements Serializable{ ZI qXkD
*{j;LA.BR#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <Opw"yY&q]
RandomAccessFile oSavedFile; (|o@
long nPos; \lQI;b;$
do.>Y}d
::iYydpM
public FileAccessI() throws IOException %e0X-tXcmX
{ [OUV!o
this("",0); 77sG;8HE
} vO&X<5?Qc
kONn7Itbu
7][fciZN
public FileAccessI(String sName,long nPos) throws IOException #I.~+M
{ }vx,i99W?
oSavedFile = new RandomAccessFile(sName,"rw"); $joGda
this.nPos = nPos; &qSf ~7/
oSavedFile.seek(nPos); 6SE^+@jR
} =54D#,[B
hCF_pt+
F%&lM[N%
public synchronized int write(byte[] b,int nStart,int nLen) jPZ+~:m+
{ n7~4*B
int n = -1; B[EOz\?=m
try{ 4g2`[<S
oSavedFile.write(b,nStart,nLen); %saP>]o
n = nLen; }qoId3iY!7
} lxgfi@@+h
catch(IOException e) ~MC5rOA
{ 59SL mj
e.printStackTrace (); Bhx.q,X
} mLkp*?sfC
'jE/Tre^
(jhi<eV
return n; KWD{_h{R
} yHC[8l8%
X"`[&l1
_z%~m2SP
} bXc*d9]
lX2:8$?X
O43"-
/* R[m{"2|,Lc
**SiteInfoBean.java =-/'$7R,
*/ {dxl8~/I
package NetFox; H Q[
<oT1&C{
B6TE9IoSb8
public class SiteInfoBean { .bP8Z=
bx{njo1Mr
_K{-1ZYsi
private String sSiteURL; //Site's URL v?6*n>R
private String sFilePath; //Saved File's Path d*04[5`
private String sFileName; //Saved File's Name $|&<cenMT
private int nSplitter; //Count of Splited Downloading File 'U ZzH$h
"s]
XRQ1Uh6
public SiteInfoBean() [_3&
{//nSplitter的缺省值为5 Zos.WS#
//default value of nSplitter is 5 >b9J!'G,(
this("","","",5); lDKyD`WKnZ
} mS;WNlm\
'q~<ZO
40`Qsv0#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) aJjUy%
{ /=AFle2(
sSiteURL= sURL; 3)o>sp)Ji$
sFilePath = sPath; [.xc`CF
sFileName = sName; SB('Nqih
this.nSplitter = nSpiltter; 6)ZaK
3dbaCusT$
:*[mvF
} 4 $Kzh
._A4:
]3='TN8aQF
public String getSSiteURL() h@1/
{ =L1%gQJJ&
return sSiteURL; )!E:
} L;vglS=l;
cmU0=js.
BQ[R)o
public void setSSiteURL(String value) `W_&^>yl
{ 9ei'oZ
sSiteURL = value; \h s7>5O^K
} \}kR'l
gpzFY"MS=
.mqMzV
public String getSFilePath() NX(+%EBcA
{ %x@bP6d[
return sFilePath; Eul3 {+]
} '~f*O0_
Ei+lVLoC
ht6}v<x.eA
public void setSFilePath(String value) 6(htpT%J
{ CKe72OC
sFilePath = value; gp 11/.
} Q7F4OS5b
m8F \ESL
e];IQ|
public String getSFileName() |E$q S)y
{ }W!w
return sFileName; a;U)#*(5|v
} +lFBH(o]X
cp~6\F;c
HA}q.L]#
public void setSFileName(String value) ?z-nY,'^uq
{ W=+AU!%
sFileName = value; f>cUdEPBb
} |?^N@
*KiY+_8>
>j ].`T
public int getNSplitter() s?1Aj<
{ hv>Xr=RE
return nSplitter; %" mki>
} lWJYT<kt
x30|0EHYl[
A0;{$/
public void setNSplitter(int nCount) fU%Ys9:wU
{ yV L >Ie/
nSplitter = nCount; .8ikcs
} ^!k_"C)B
} H=WB6~8)
?5lO1(
n!X%i+|4x
/* HpUJ_pZ
**Utility.java o.|36#Fa
*/ QKvaTy#
package NetFox; uX{g4#eG
TPkP5w
A~k: m0MX
public class Utility { 7TypzgXNe
H|j]uLZ
'|v<^EH
public Utility() zT/woiyB`
{ =c#mR" 1
|t3}>+"?z
|FlB#
} RhF<{U.
mKV31wvK}
//线程睡眠 pK_zq
public static void sleep(int nSecond) rij%l+%@#
{ iny/K/5bf
try{ %zEy.7Ux
Thread.sleep(nSecond); %'=TYvB 2
} U Lq`!1{
catch(Exception e) QJR},nZ3
{ O)&ME
e.printStackTrace (); uP8 cW([
} tx+P@9M_Aq
} }waZGJLN
}> C?Zx*
//日志 t)k;5B`> &
public static void log(String sMsg) egfd=z=2un
{ 4PU@W o
System.err.println(sMsg); D0S^Msk9L
} ~WV1t][
k@n L(2
"OkZ [E)
public static void log(int sMsg) ix?Z:pIS0
{ :c )R6=v
System.err.println(sMsg); UaQW<6+
} z1tCSt}7f
} *?Wr^T
r,vSDHb`j
h.- o$+Sa
/* =bvLMpa
**TestMethod.java qf[J-"o
*/ 7+[L6q/K
package NetFox; o?.VW/"
XJS^{=/
_wW"Tn]
public class TestMethod { $mf6!p4
ci 22fw0
m<cv3dbZo
public TestMethod() Xfg?\j/
{ ///xx/weblogic60b2_win.exe ^y|`\oyqwN
try{ *8%uXkMm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V!+<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fbah~[5}
SiteFileFetch fileFetch = new SiteFileFetch(bean); '?{L gj^R
fileFetch.start(); -I#<?=0B
} m,w^,)
catch(Exception e){e.printStackTrace ();} }>YEtA
@fVz *
K3rsew n
} 6BXZGE
pm=s
UK@hnQU8`
public static void main(String[] args) yB;K|MXy?
{ =3;! 5P
new TestMethod(); `VglE?M
} ?$/W3Xn0%
} w0<1=;_%
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