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)); p"T4;QBxQ
} G*QQpSp
for(int i=0;i<nEndPos.length-1;i++) gC 4w&yL
{ 4l|Am3vzX
nEndPos = nStartPos[i+1]; `27? f$,
} Kl*##qw!
nEndPos[nEndPos.length-1] = nFileLength; 9u9#&xx
} "x{S3v4Rb5
} /4|qfF3
FUDMaI
qG;WX n
//启动子线程 -x7L8Wj
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e1H.2n{y^
for(int i=0;i<nStartPos.length;i++) K= 69z
{ ~"-wSAm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =Rui
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ''Hq-Ng
nStartPos,nEndPos,i); |$D^LY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z#F2<*+Pe
fileSplitterFetch.start(); {PfE7KH
} lU@ni(69d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A81kb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OvFZ&S[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", DzYno-]A]
nEndPos = " + nFileLength); #i~.wQ$1
// fileSplitterFetch[nPos.length-1].start(); Y A;S'dxY
O9opX\9
Abj`0\
//等待子线程结束 kJ~^ }o
//int count = 0; %1#5 7-
//是否结束while循环 I3SLR
boolean breakWhile = false; D3I;5m`_
GE"#.J4z
p<$z!|7m
while(!bStop) iJq}tIk#2'
{ ^7(zoUn:
write_nPos(); N^)L@6
Utility.sleep(500); ?4xTA
breakWhile = true; W1Ht8uYG3
& K7+V
&359tG0@P
for(int i=0;i<nStartPos.length;i++) 75{QBlf<
{ |vzGFfRI
if(!fileSplitterFetch.bDownOver) $ZE OE8.\
{ +lE 9*Gs_$
breakWhile = false; Ua(!:5q?
break; 5HmX-+XpK
} rNZN}g
} hMi[MB7~
if(breakWhile) f4uK_{
break; iX~V(~v
n-p|7N
MvObx'+
//count++; p=eSHs{>A
//if(count>4) KO:o GUR
// siteStop(); .4U::j}
} cp[k[7XGD
2TY|)ltsF
pnDD9u-4;
System.err.println("文件下载结束！"); %<K`d
} ~`T3 i
catch(Exception e){e.printStackTrace ();} ~g)gXPjke
} q S2#=
'%kk&&3'
~^Gk7
//获得文件长度 6EJ,czt(
public long getFileSize() p.&FK'&[0
{ Vhv<w O Ct
int nFileLength = -1; N3i}>Q)B
try{ 9V("K
URL url = new URL(siteInfoBean.getSSiteURL()); H7*/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :jgwp~l
httpConnection.setRequestProperty("User-Agent","NetFox"); @ScH"I];uA
<[kdF")
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int responseCode=httpConnection.getResponseCode(); r6QNs1f~.
if(responseCode>=400) BY72fy#e
{ vfm|?\
processErrorCode(responseCode); }JoCk{<31
return -2; //-2 represent access is error 4)i/B99k
} &p`RKD
PO]z'LD
D8qZh1w%A|
String sHeader; jv?`9{-
#GY;.,
f_7a) 'V4
for(int i=1;;i++) v4DF #O
{ PJsiT4<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bwS1YGb
//Utility.log(in.readLine()); a3sXl+$D@
sHeader=httpConnection.getHeaderFieldKey(i); H~e;S#3_v
if(sHeader!=null) &%$r3ePwc
{ ci <`*>l
if(sHeader.equals("Content-Length")) /T!S)FD\/v
{ f^Lw3|rq4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); DI"mi1ObE
break; rB~x]5TH
} ZC@sUj"
} Re0ma%~LP
else %c*azo.
break; U5[xW
} FcB]wz
} j ~:Dr
catch(IOException e){e.printStackTrace ();} c~K^ooS-
catch(Exception e){e.printStackTrace ();} _ko16wfg
ML^c-xY(
.;8T*
Utility.log(nFileLength); !'Q/9%g
y+hC !-
lED-Jo2
return nFileLength; =X'i^Q
} iP6$;Y{ZA
A]id*RtY
Z_.Eale^
//保存下载信息（文件指针位置） Y9F!HM-`
private void write_nPos() Z?kLAhy!
{ X>(?
try{ q$(@
output = new DataOutputStream(new FileOutputStream(tmpFile)); ],YIEOx6
output.writeInt(nStartPos.length); QqA~y$'ut
for(int i=0;i<nStartPos.length;i++) &`[y]E'
{ RcIGIt
// output.writeLong(nPos); HS =qK
output.writeLong(fileSplitterFetch.nStartPos); 8M9 &CsT6
output.writeLong(fileSplitterFetch.nEndPos); =\GuIH2
} q-P$ \":
output.close(); $@<qaR{t\
} |r[yMI|VR
catch(IOException e){e.printStackTrace ();} -]\cUQ0
catch(Exception e){e.printStackTrace ();} St}j^i
} @.T(\Dq^
@AYO )Y8
!VUxy
//读取保存的下载信息（文件指针位置） |-GmWSK_
private void read_nPos() `!rH0]vy
{ phr6@TI
try{ JDrh-6Zgj
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }<6xZy
int nCount = input.readInt(); !g{9]"Z1T
nStartPos = new long[nCount]; 4)./d2/E
nEndPos = new long[nCount]; STmn%&
for(int i=0;i<nStartPos.length;i++) (jv!q@@2C.
{ g"gh2#!D
nStartPos = input.readLong(); S(<r-bV<
nEndPos = input.readLong(); b<o Uy
} W!|A3V35\:
input.close(); 02OL-bv}HS
} # ~SuL3
catch(IOException e){e.printStackTrace ();} ENW>bS8e`
catch(Exception e){e.printStackTrace ();} wN1%;~?7
} k9H7(nS{
e]R`B}vO
_X5@%/Vz
private void processErrorCode(int nErrorCode) dXR70/
{ }`M53>C,gQ
System.err.println("Error Code : " + nErrorCode); Gh;Ju[6
} _):V7Zv
3~ITvH,`s
)QS4Z{)U
//停止文件下载 mv9k_7<
public void siteStop() z*?-*6W
{ C%P)_)--V
bStop = true; "J:~Aa%_
for(int i=0;i<nStartPos.length;i++) &<8Q/m]5
fileSplitterFetch.splitterStop(); PR rf$& u
j/"{tMqQp
g}HB|$P7
} t<S]YA~N'
} +%vBDcf
//负责部分文件的抓取 $B6CLWB
**FileSplitterFetch.java .Y B}w
*/ wcGI2aflD
package NetFox; ~<b/%l>h1
lR]z8&
Fe8JsB-
import java.io.*; Q(@/,%EF
import java.net.*; VxD_:USIF
eeIaH >
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public class FileSplitterFetch extends Thread { u{Jv6K,
l|#WQXs*c{
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String sURL; //File URL w`Q"mx*
long nStartPos; //File Snippet Start Position +Kc1a;
long nEndPos; //File Snippet End Position 5Z2E))UU
int nThreadID; //Thread's ID lZT9 SDtS
boolean bDownOver = false; //Downing is over #hinb[fQ
boolean bStop = false; //Stop identical HSq.0vYl6
FileAccessI fileAccessI = null; //File Access interface ua$H"(#c
4o,%}bo&
3w&fN3 1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |n9~2R
{ 3f'dBn5
this.sURL = sURL; YTBZklM
this.nStartPos = nStart; ^/;W;C{4
this.nEndPos = nEnd; !eb}jL
nThreadID = id; e">$[IhXtV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 om3$=
} +uR|0Jo8X
vIBVp
ml7nt0{
public void run() @V$,H/v:
{ Fy4jujP<
while(nStartPos < nEndPos && !bStop) x;H#-^LxW=
{ k<b`v&G
0,)Ao8
$`q8-+{
try{ S<n3wR"^
URL url = new URL(sURL); rE?(_LI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .H1kl)~V
httpConnection.setRequestProperty("User-Agent","NetFox"); cv fh:~L
String sProperty = "bytes="+nStartPos+"-"; ibDMhW$n
httpConnection.setRequestProperty("RANGE",sProperty); <0[{Tn
Utility.log(sProperty); qX'w}nJ}H}
)tQG5.to
/EY^ui
InputStream input = httpConnection.getInputStream(); nJ/wtw
//logResponseHead(httpConnection); D;bQ"P-m47
U^_'e_)
>:l;W4j
byte[] b = new byte[1024]; |xI\)VE^
int nRead; \=+s3p5N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?sl 7C gl
{ iQ= %iou
nStartPos += fileAccessI.write(b,0,nRead); D .3Q0a6
//if(nThreadID == 1) %gd=d0vm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O[RmQ8ll
} $)| l#'r
^G63GYh]y
s{q)m@
Utility.log("Thread " + nThreadID + " is over!"); 9%\<x
bDownOver = true; dfB#+wh
//nPos = fileAccessI.write (b,0,nRead); yhr\eiJ@6
} ,x5`5mT3
catch(Exception e){e.printStackTrace ();} db"FC3/H
} ~CRr)(M
} jY-i`rJN
,hK0F3?H>
8?']W\)
//打印回应的头信息 [KkLpZG
public void logResponseHead(HttpURLConnection con) p$}iBk0B(z
{ gf+Kr02~
for(int i=1;;i++) /U<-N'|
{ =Mq=\T
String header=con.getHeaderFieldKey(i); /:>f$k4~h
if(header!=null) F#_7mC
//responseHeaders.put(header,httpConnection.getHeaderField(header)); LBtVK, ?
Utility.log(header+" : "+con.getHeaderField(header)); ]}9cOb%I
else JGIN<J85e
break; _1*EMq6
} P0$q{ j
} w5jH#ja
_,b%t1v
>q <,FY!A
public void splitterStop() s)yEVh
{ e =& abu
bStop = true; ?)Lktn9%
} AW6]S*rh
W<;i~W
n4)G g~PE
} BW:&AP@B
sCaw"{5qc
Z!6\KV]
/* {a_=4a
**FileAccess.java iAf, :g
*//文件访问(定位，写) IGql^,b
package NetFox; T~Jl{(s9)
import java.io.*; HeGGAjc
? $pGG
F$ Us! NN
public class FileAccessI implements Serializable{ &X_I^*
j]J2,J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ix^:qw;
RandomAccessFile oSavedFile; )QaJYC^+
long nPos; dz5bW>
]G&?e9OA
n5UcivyX
public FileAccessI() throws IOException F.?:Gd1
{ "rc}mq
this("",0); 8[f]9P/i
} (5-"5<-@R
o'myo.k{
/c/!13|
public FileAccessI(String sName,long nPos) throws IOException |Y/iq9l
{ k4pvp5}%
oSavedFile = new RandomAccessFile(sName,"rw"); HJBUN1n
this.nPos = nPos; j/9FiuK
oSavedFile.seek(nPos); &[S)zR=?
} $g#X9/+<
,2H5CFX/
:+]6SC0ql
public synchronized int write(byte[] b,int nStart,int nLen) }M'\s
{ /CKkT.Le
int n = -1; o,bV.O.W
try{ }}grJh>tGg
oSavedFile.write(b,nStart,nLen); }kL%l
n = nLen; K+T`'J4
} .j7|;Ag
catch(IOException e) ]}>GUXe)^
{ Vl^jTX5N
e.printStackTrace (); s.zH.q,
} -Rjn<bTIy
Yz-b~D/=}
7jts;H=
return n; B+zq!+ HJ
} &??(EA3
z_JZx]*/
3w{i5gGn
} Bu!Gy8\
B TcxBh
gvA&F|4
/* A|RAMO@le
**SiteInfoBean.java |C>Yd*E,C
*/ A.WJ#1i}E
package NetFox; ;HqK^[1\
Y 3KCIL9
)}WG`
public class SiteInfoBean { ?1PY]KNaK
<YJU?G:@
3kYUO-qw
private String sSiteURL; //Site's URL [&FMVM`
private String sFilePath; //Saved File's Path @ULr)&9
private String sFileName; //Saved File's Name hCr7%`
private int nSplitter; //Count of Splited Downloading File 'Iu$4xo`[
uY "88|
T w"^I*B
public SiteInfoBean() 7!MW`L/`
{//nSplitter的缺省值为5 0JNG\ARC
//default value of nSplitter is 5 deeOtco$LT
this("","","",5); /}M@ @W
} II~D66 bF
GueqpEd2
hrcR"OZ~X
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bd)A6a\h
{ ~f%gW
sSiteURL= sURL; <7TpC@"/g
sFilePath = sPath; ej!C^
sFileName = sName; :_Ng`b/
this.nSplitter = nSpiltter; Q3oVl^q
e?Cbl'
Ns1u0$fg
} vNJ!i\bX
FirmzB Il5
&+*jTE
public String getSSiteURL() Xv:<sX
{ vhhsOga
return sSiteURL; r."Dc
} ;TaT=%
1Z`<HW"
MR+ndB<
public void setSSiteURL(String value) =cRJtn
{ !T @|9PCp
sSiteURL = value; 'MG)noN5
} },[j+wx
:5"|iRP'
`^w5/v#
public String getSFilePath() Q) FL|
{ 0V`/oaW;
return sFilePath; _Thc\{aV#
} YQYN.\
QiwZk<rb
0Y"==g+>f
public void setSFilePath(String value) L'['7
{ YjG0: 9
sFilePath = value; YHeB<v
} GbNVcP.ocP
5(DCq(\P*
Q7#Q6-Q
public String getSFileName() M)3h 4yQ
{ v3aiX
return sFileName; MK=:L
} X\YeO>C
]CHMkuP[k
;GE0iSC
public void setSFileName(String value) LXw&d]P
{ ];Z_S`JR
sFileName = value; Is88+,O
} w@oq.K
du47la 3
xp,H5 m%
public int getNSplitter() sY1*WolA
{ o.j;dsZ
return nSplitter; lkl#AH
} Mb/R+:C`
+ ^~n09
E>7%/TIl
public void setNSplitter(int nCount) TmUn/
{ K$K[fcj
nSplitter = nCount; Zl* HT%-5
} W;0_@!?mr}
} T>LtN
oTfEX4 t {
`d8$OC
/* 57r\s8
**Utility.java }RM?gE
*/ ok[R`99
package NetFox; ,rTR |>Z
9N-mIGJ
0eb`9yM
public class Utility { Lqz}h-Ei
2>s:wABb /
XSZW9/I-(|
public Utility() 67f#Z&r2k
{ irrQ$N}
=I*"vwc?
KXR
} 2#|Q=rWB
h{>8W0W*
//线程睡眠 +n%WmRf6!
public static void sleep(int nSecond) P:CwC"z>sS
{ znu?x|mV
try{ jIuE1ve
Thread.sleep(nSecond); (+T|B E3*#
} @dO~0dF
catch(Exception e) 0R*!o\y
{ sd#a_
e.printStackTrace (); |ukEnjI`u
} Ak|jJ
} od-N7lp#
Dwwh;B
//日志 03{e[#6
public static void log(String sMsg) 6h;$^3x$
{ q \0>SG
System.err.println(sMsg); n {^D_S
} u,/PJg-(!
i) :Q{[D
_L&C4 <e'
public static void log(int sMsg) $g#%
{ -S9$C*t
System.err.println(sMsg); @'~v~3 $S
} %hOe `2#$
} vE&
`ZNzDr
? NVN&zD]
/* ~ dmyS?Or
**TestMethod.java E+[K?W5
*/ #O`nQ
package NetFox; Z wIsEJz
+FyG{1?<
{6v+ Dz>
public class TestMethod { oGXT,38*
72luTR Q
9<,\+}^{
public TestMethod() }J"}poB:
{ ///xx/weblogic60b2_win.exe keCM}V`?"
try{ ~?S/0]?c
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q=g;TAXZl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); XG_lyx%:E
SiteFileFetch fileFetch = new SiteFileFetch(bean); /ey}#SHm,
fileFetch.start(); zjB8~ku#
} @k~Xem%<
catch(Exception e){e.printStackTrace ();} :/d#U:I
dsrzXmE0
mI9~\k&9
} ocGqXDg3
;S2^f;q~$
%A:<rO85o
public static void main(String[] args) I@7^H48\
{ 2NqlE
new TestMethod(); M)( 5S1ndq
} ->$Do$
} f*LDrAf9
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