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)); 'RjMwJy{
} M~ ^ {S[o
for(int i=0;i<nEndPos.length-1;i++) ZPolE_P7
{ JJn+H&[B
nEndPos = nStartPos[i+1]; 7IV:X _y
} 9e xHR&>{
nEndPos[nEndPos.length-1] = nFileLength; i@|.1dWh
} xgQ]#{tG
} KJLK]lf}d
ko<iG]Dv'
-ipfGb
//启动子线程 zMI0W&P M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ( O>oN~
for(int i=0;i<nStartPos.length;i++) OJH:k~]0!
{ eODprFkt}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^68BxYUoD\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c?1:='MC
nStartPos,nEndPos,i); xw%'R-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %hqhi@q#
fileSplitterFetch.start(); NA`EG,2
} xK8R![x
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S3(2.c~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >|e>=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t<Z)D0.
nEndPos = " + nFileLength); \p&a c&]
// fileSplitterFetch[nPos.length-1].start(); }:5>1FfX=
;*8nd-\
!Ho=(6V
//等待子线程结束 mp x/~`c
//int count = 0; Q(e3-a
//是否结束while循环 0Q_@2
boolean breakWhile = false; al3[Ph5G
nPj/C7j
LbeMP
while(!bStop) 0- 'f1 1S
{ ,B<Tt|'
write_nPos(); &3;yho8v@
Utility.sleep(500); G$buZspL'd
breakWhile = true; 389puDjy
`*1059
^9Je8 @Yu
for(int i=0;i<nStartPos.length;i++) "[LSDE"(
{ VC6S4FU4K
if(!fileSplitterFetch.bDownOver) @$(/6]4p
{ +yYv"J
breakWhile = false; 8'kA",P
break; &2!F:L
} .7nr:P
} &$?i
if(breakWhile) "w\Iz]
break; ]GS@ub
.2jG~_W[
pSq3\#Twr
//count++; #^bkM)pc
//if(count>4) [@qUQ,Ie
// siteStop(); bh8IF,@a
} 32flOi:
Odo"S;)
')ErXLP_
System.err.println("文件下载结束！"); &dV|~xA6N
} FB0y
catch(Exception e){e.printStackTrace ();} I2!0,1Q
} Yz?1]<X
1/bu}?a
mYudUn4Wo
//获得文件长度 c9dH ^t
public long getFileSize() ~la=rh3
{ Wh,{|R[
int nFileLength = -1; :q2tda
try{ cJ%u&2J_
URL url = new URL(siteInfoBean.getSSiteURL()); .+H8c.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ='7n
httpConnection.setRequestProperty("User-Agent","NetFox"); USnKj_e
.bm#|X)RO
<9S?wju4W'
int responseCode=httpConnection.getResponseCode(); KJwkkCE/=
if(responseCode>=400) I]`>m3SJ
{ ~[i,f0O,
processErrorCode(responseCode); z:aT5D
return -2; //-2 represent access is error COw]1R
} 9GdrJ~h
S!GjCog^J
'U)|m
String sHeader; *XmOWV2Y_
+|OkT
Bu'PDy~W,
for(int i=1;;i++) / 4K*iq
{ 3:rH1vG.m
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j/bebR}X
//Utility.log(in.readLine()); sBuVm<H
sHeader=httpConnection.getHeaderFieldKey(i); F*QD\sG:
if(sHeader!=null) sX3Vr&r
{ j~G^J
if(sHeader.equals("Content-Length")) F6T@YSP
{ bp6 La`+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $a6&OH/
break; @NXGVmY1}
} $J#}3;a
} \<VwGbzFi
else ?S8cl7;+
break; Y962rZ
} j\nnx8`7
} RGGP6SDc
catch(IOException e){e.printStackTrace ();} &50Kn[
catch(Exception e){e.printStackTrace ();} )S$!36Ni[
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}TRr*] P<%
Utility.log(nFileLength); W|T"'M_
.ukP)rGe
[&rW+/
return nFileLength; 0>-l {4srs
} l%"eQ
`}F=Zjy
0+O)~>v
//保存下载信息（文件指针位置） J-fU,*Bk
private void write_nPos() c7IgndVAV
{ jow^~
try{ \PzC:H
output = new DataOutputStream(new FileOutputStream(tmpFile)); &_&])V)<\S
output.writeInt(nStartPos.length); `X]-blHo
for(int i=0;i<nStartPos.length;i++) F'Fc)9qFa<
{ WjGv%^?
// output.writeLong(nPos); J%xp1/=2
output.writeLong(fileSplitterFetch.nStartPos); .9WUp>
output.writeLong(fileSplitterFetch.nEndPos); |rf\]3 F
} ~aH*ZA*f
output.close(); 5/mW:G,&
} "HVwm>qEi
catch(IOException e){e.printStackTrace ();} pi5Al)0
catch(Exception e){e.printStackTrace ();} SGH"m/ e
} ?M7nbfy[A@
V0L^pDLOV
"8Pxf=
//读取保存的下载信息（文件指针位置） U;KHF{Vm
private void read_nPos() j2#Vdw|j
{ qo.~5
try{ 6(oGU4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L5cNCWpo
int nCount = input.readInt(); y]?%2ud/=
nStartPos = new long[nCount]; 9L?EhDcDV
nEndPos = new long[nCount]; <l5{!g
for(int i=0;i<nStartPos.length;i++) &P!^k0NJR
{ p&_a kQj
nStartPos = input.readLong(); 0(3t#
nEndPos = input.readLong(); G4s!q1H
} *E.{i
input.close(); (EUX>IJ
} K;-:C9@
catch(IOException e){e.printStackTrace ();} YFLWkdqAY
catch(Exception e){e.printStackTrace ();} -MHu BgYJ-
} gSu+]N
.gT@_.ZD9
e\.|d<N?
private void processErrorCode(int nErrorCode) pZGso
{ 5cyl:1Ln
System.err.println("Error Code : " + nErrorCode); .4F(Y_c
} t2+m7*76
nI.#A
rN{&$+"2
//停止文件下载 #>~$`Sg
public void siteStop() h&yaug,.
{ Y*f7& '[
bStop = true; >K-O2dry*
for(int i=0;i<nStartPos.length;i++) %9BC%w]y
fileSplitterFetch.splitterStop(); C-_u; NEu
#B'WT{B$/~
zv#i\8h^p
} &66G
} uzZ|w+3O
//负责部分文件的抓取 GWA_,/jS%
**FileSplitterFetch.java fylW)W4C
*/ |fTQ\q]W
package NetFox; r9s1\7]x
V}9wx%v
\s<iM2]Kl
import java.io.*; G~4^`[elB
import java.net.*; X.Z?Ie
v_5DeaMF'
":"M/v%F
public class FileSplitterFetch extends Thread { sNX$ =<E
R,Tw0@{O*
,3GM'e{hV
String sURL; //File URL $j{ynh)^
long nStartPos; //File Snippet Start Position R) @k|
long nEndPos; //File Snippet End Position d-N<VVcy\
int nThreadID; //Thread's ID ])~*)I~Y
boolean bDownOver = false; //Downing is over Q6%m}R
boolean bStop = false; //Stop identical K]kL?-A#'
FileAccessI fileAccessI = null; //File Access interface )CdglPK
O:lD>A4{
f 21w`Uk48
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1 ,D2][
{ "!Mu5Ga
this.sURL = sURL; uaJ5'*
this.nStartPos = nStart; A7|"0*62
this.nEndPos = nEnd; #wM0p:<
nThreadID = id; .D4D!!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $!obpZ~}
} v l{hE~
o{UwUMw5`
3O#7OL68v
public void run() 4sZ^:h,1
{ >454Yir0Mk
while(nStartPos < nEndPos && !bStop) T| 4c\
{ L?9Vz&8]
m>NRIEA6
s|,gn5
try{ X[Y!=e4z
URL url = new URL(sURL); ]vT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fRrHWE+
httpConnection.setRequestProperty("User-Agent","NetFox"); XJ@ /r,2
String sProperty = "bytes="+nStartPos+"-"; fEQ<L!'
httpConnection.setRequestProperty("RANGE",sProperty); !0Q(x
Utility.log(sProperty); k92X)/ll'
C(,s_Ks
um3 M4>K
InputStream input = httpConnection.getInputStream(); o"n^zG
//logResponseHead(httpConnection); -Qn:6M>w^
0^["&K/
YuPgsJ[m
byte[] b = new byte[1024]; *[yCcqN.
int nRead; YT:<AJm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qU2>V
{ C7+TnJ
nStartPos += fileAccessI.write(b,0,nRead); k9R1E/;
//if(nThreadID == 1) 1Tiq2+hmf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pd7FU~-
} >Q5 SJZ/
]E=JUYf0
oTx#e[8f{
Utility.log("Thread " + nThreadID + " is over!"); lc5NC;JR
bDownOver = true; aL=VNZ!Pqc
//nPos = fileAccessI.write (b,0,nRead); a-QHm;_S
} o@pM??&x
catch(Exception e){e.printStackTrace ();} Rut6m5>
} / m?Z!
} j/Bzbjq"
5@Py`
Nr(WbD[T
//打印回应的头信息 8sbS7*#
public void logResponseHead(HttpURLConnection con) m,up37-{
{ %eT/:I
for(int i=1;;i++) x!YfZ*
{ qHHWe<}OT
String header=con.getHeaderFieldKey(i); ,vN#U&RS
if(header!=null) ( I,V+v+{Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;H\,w/E9
Utility.log(header+" : "+con.getHeaderField(header)); #d|.BxH
else 1^Caz-
break; d[$1:V
} ^R<= }
} y"9TS,lmK
9Hc#[Ml
9MXauTKI
public void splitterStop() C)ChF`Ru':
{ w[|!$J?
bStop = true; 1m![;Pg3
} 'GW@P
#x%O0
{UPIdQ'g
} HQUL?URt
41C=O@9m
?xG #4P<C=
/* OdR
**FileAccess.java MPGQ4vi&
*//文件访问(定位，写) 7rr5$,Mv
package NetFox; ZjI^0D8
import java.io.*; <XLATS8Y
|Xu7cCh$me
]\3dJ^q|%
public class FileAccessI implements Serializable{ iySmNI
;hZ(20
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~;`i&s
RandomAccessFile oSavedFile; BM3)`40[]
long nPos; Jhut>8
XM=`(e o
nwkhGQ
public FileAccessI() throws IOException P4N{lQ.>
{ oNEU?+
this("",0); ] 2b@mX
} ?3zx?>sG
4l3N#U0Q
twN(]w}Ps|
public FileAccessI(String sName,long nPos) throws IOException CRqa[boU*
{ MBwp{ET!p
oSavedFile = new RandomAccessFile(sName,"rw"); Fvv6<E
this.nPos = nPos; XSD7~X/:
oSavedFile.seek(nPos); Xg%zE
} 2]C0d8=*?
j<gnh
#pVk%5N
public synchronized int write(byte[] b,int nStart,int nLen) >5N}ZIN
{ iL\\JuY
int n = -1; >i ~zG6H
try{ Y}WO`+Vf5
oSavedFile.write(b,nStart,nLen); Lh,<q >t
n = nLen; Jq; }q63:
} /y-P)3_
catch(IOException e) X:!%"K%}
{ "xO`&a{
e.printStackTrace (); VtmUK$k}I
} [ z&y]~
}0!\%7-Q
8t7hN?,t
return n; AV&ege
} =AAH}
nv8,O=#s
+,KuYa{lu
} +X- k)9
![V<vIy
+0a',`yc
/* p1D-Q7F
**SiteInfoBean.java !C+25vup
*/ Wx-{F
package NetFox; J7maG|S(DF
h*KhH>\
Ln: y|t
public class SiteInfoBean { Gs9jX/#
u*U?VZ5
Y{S/A*X
private String sSiteURL; //Site's URL );*GOLka
private String sFilePath; //Saved File's Path D0-e,)G}V,
private String sFileName; //Saved File's Name IQ~()/;3d
private int nSplitter; //Count of Splited Downloading File >/n/n{{
w5|"cD#8A
vTP_vsdeG
public SiteInfoBean() )a6i8b3
{//nSplitter的缺省值为5 |On6?5((e
//default value of nSplitter is 5 mPh;
this("","","",5); KA<
} H_2hr[
<zUmcZ
TRiB|b]8Q#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +GGj*sD
{ \"*l:x-u
sSiteURL= sURL; 'nLv0.7*
sFilePath = sPath; Gah e-%J
sFileName = sName; Kfr?sX
this.nSplitter = nSpiltter; N" 8o0>
aL`pvsnF
t3WlVUtq3
} L\B+j+~
]x Kmz
xpnnWHdaq
public String getSSiteURL() [_~U<
{ DUtpd|
return sSiteURL; #}gc6T~0
} ox*Ka]
|~/{lE=I
{u1t.+
public void setSSiteURL(String value) *83+!DV|
{ 7+fik0F
sSiteURL = value; ,yT4(cMBk?
} jgYiuM3c\
$@NZ*m%?JQ
N7;2BUIXJ
public String getSFilePath() M-Js"cB[
{ Pf!K()<uJ
return sFilePath; w9oiu$7),
} qzLRA.#f^
X}Csl~W8in
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public void setSFilePath(String value) oT_,k}LIX
{ OW.ckYt%
sFilePath = value; l nZ=< T
} vKW%l
;L`'xFo>>
1zM`g_(#
public String getSFileName() t (1z+
{ (PNvv/A
return sFileName; h%O`,iD2
} olJ9Kfc0
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j` x9z_
public void setSFileName(String value) <)}*S
{ a0n F U
sFileName = value; sv[)?1S
} Oo0$n]*;W
<E^:{J95
x?%vqg^r
public int getNSplitter() tsk}]@W
{ QL)UPf>Kp
return nSplitter; I?PKc'b
} GM%|mFqeu
z#\Z|OKU
S38D cWIw
public void setNSplitter(int nCount) +]__zm/^
{ %d>Ktf
nSplitter = nCount; "au"\}
} z XvWo6
} ,Bta)
@#V{@@3$
0>'1|8+`(z
/* YcGqT2oLP
**Utility.java =thgNMDm"
*/ tQ)8HVKF
package NetFox; e"bF"L
-1{N#c/U
5|Y4GQVz
public class Utility { b+C>p2%
dv,8iOL
IlE! zRA
public Utility() p7k0pSt
{ Q`oi=OYB
a"v D+r7Ol
dFUsQ_]<
} IOJfv8
s<5t}{x
//线程睡眠 x,>=X`T
public static void sleep(int nSecond) 2M;{|U
{ mr/^lnO
try{ 1xx-}AIH#
Thread.sleep(nSecond); T.{I~_
} tVe*J@i\$
catch(Exception e) ,:#prT[P"
{ K.cNx
e.printStackTrace (); <1@_MYo
} GJW1|Fk
} E:i3 /Ep?
KctD=6
//日志 ^C'k.pV n~
public static void log(String sMsg) 4Q]+tXes
{ "_(o% \"7
System.err.println(sMsg); kL&^/([9
} v/^2K,[0>
y/PEm)=Tt
n3)g{K^
public static void log(int sMsg) ~U^0z|.
{ #v v k7
System.err.println(sMsg); -_2=NA?t
} RuHJk\T+
} a-YK*
p<![JeV
wRuJein#
/* LAr6J
**TestMethod.java YY.;J3C
*/ 2=#O4k.@
package NetFox; `R; ct4-
{g);HnmPN
o30PI
public class TestMethod { v5*SoUOF
1.';:/~(
ckTnb
public TestMethod() u?aq' "t
{ ///xx/weblogic60b2_win.exe B0YY7od
try{ Fc nR}TE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); plp).Gq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xi.;`Q^#
SiteFileFetch fileFetch = new SiteFileFetch(bean); hTy#Q.=
fileFetch.start(); 7?kvrIuY&
} s{CSU3vYmi
catch(Exception e){e.printStackTrace ();} Z1>pOJm
,{.&xJ$
EJ86k>]
} KcSvf;sx
(K2 p3M^
CUYp(GU
public static void main(String[] args) zZDr=6|r_
{ ."H5.'
new TestMethod(); hZ%Ie%~n
} ;/YSQt)rc>
} Cd(Ov5%
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