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)); dpW`e>o
} upMs yLp(
for(int i=0;i<nEndPos.length-1;i++) ]-wyZ +a
{ )u(,.O[cw
nEndPos = nStartPos[i+1]; (Aw@}!
} \;XJ$~>
nEndPos[nEndPos.length-1] = nFileLength; k)+{Y v*
} c44s@E
} g0 Q,]\~
(6fD5XtS
"smU5 s,P
//启动子线程 xhALJfv
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -o/Vp>_UOE
for(int i=0;i<nStartPos.length;i++) LuRCkKJ
{ / :$WOQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x1~AY/)v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), IR"C?
nStartPos,nEndPos,i); 7^>~k}H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ktk?(49
fileSplitterFetch.start(); gPn0-)<
} +=W(c8~P
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BiU>h.4=$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _#~D{91 j:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3uw3[ SR1
nEndPos = " + nFileLength); kiF}+,z"
// fileSplitterFetch[nPos.length-1].start(); +wj}x?ZeV
(%6fZ
U2`:'
//等待子线程结束 b0}dy\dnQ
//int count = 0; TTO8tT3[6}
//是否结束while循环 -[*y{K@dh
boolean breakWhile = false; 3_RdzW}f
&tUX(
2?qT,pN
while(!bStop) I*3>>VN
{ [#!Y7Ede
write_nPos(); q>+!Ete1p
Utility.sleep(500); NP3 e^
breakWhile = true; HMD$vMK6
/{j._4c
)W_akUL
for(int i=0;i<nStartPos.length;i++) kh}h(z^
{ otaRA
if(!fileSplitterFetch.bDownOver) ?yG[VW
{ #)L}{mHLM-
breakWhile = false; {*;K>%r\o
break; fNda&
} \hBzQ%0
} y.(<
if(breakWhile) gDJ} <^
break; InL_JobE8r
%4R1rUrgt|
id,'+<
//count++; C`ZU.|R
//if(count>4) OGW3Pe0Z'
// siteStop(); o]I8Ghk>/z
} vMY!Z1.*
CY=lN5!J
I\Y N!
System.err.println("文件下载结束！"); ,+d8
} \R9izuc9
catch(Exception e){e.printStackTrace ();} l_;6xkv4
} 97HI9R
ld"rL6
K#6@sas
//获得文件长度 k{{ Y2B?C
public long getFileSize() ` ,SNqi
{ 3 [#Rm>,Vu
int nFileLength = -1; P(-
try{ /j3",N+I
URL url = new URL(siteInfoBean.getSSiteURL()); ZJ+ad,?,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J(8?6&=ck
httpConnection.setRequestProperty("User-Agent","NetFox"); k&L/JzzI
-G7)Y:
KL!cPnAUu
int responseCode=httpConnection.getResponseCode(); \HrtPm`e
if(responseCode>=400) cBbumf9C
{ Xhyn! &H5
processErrorCode(responseCode); amExZ/
return -2; //-2 represent access is error t>a D;|Y
} Oc,HnyV+
uF[*@N
e?7NW
String sHeader; g9;s3qXiG
sZ7,7E|_
XgXXBKf$
for(int i=1;;i++) Z0v?3v}9^
{ ]1zud
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #l`\'0`.
//Utility.log(in.readLine()); 30SQ&j[N]
sHeader=httpConnection.getHeaderFieldKey(i); ~K5A$s2
if(sHeader!=null) QrFKjmD<
{ Y^DGnx("m
if(sHeader.equals("Content-Length")) #=0 BjW*
{ bLGC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O8>&J-+2
break; K;Hgq4
} - q(a~Ge
} :.=j)ljTx
else t_16icF9U
break; F?jD5M08t/
} bJ9*z~z)e
} Q`.q,T8I
catch(IOException e){e.printStackTrace ();} r|]YS6
catch(Exception e){e.printStackTrace ();} liy/uZ
.v}|Tp&k
{jwLVKT$
Utility.log(nFileLength); x)N QRd
VR1[-OE
z6;hFcO
return nFileLength; oC} u
} q7_Ttjn-DV
$B<:SuV#
bZAL~z+ V
//保存下载信息（文件指针位置） ?WqaT)l~
private void write_nPos() XHdhSFpm
{ ?*xH HI/
try{ 01&E.A
output = new DataOutputStream(new FileOutputStream(tmpFile)); |N)),/R_
output.writeInt(nStartPos.length); _Yp~Oj
for(int i=0;i<nStartPos.length;i++) JKrS;J^97v
{ ~b X~_\
// output.writeLong(nPos); .}Xf<G&
output.writeLong(fileSplitterFetch.nStartPos); yH43Yo#Rk
output.writeLong(fileSplitterFetch.nEndPos); @TXLg2
} Ac*J;fI
output.close(); \/\w|j
} %K=_
catch(IOException e){e.printStackTrace ();} .L;e:cvx
catch(Exception e){e.printStackTrace ();} @OFxnF`
} X6(s][Wn
\G)F*
u8%X~K\
//读取保存的下载信息（文件指针位置） S3WUccv
private void read_nPos() Z^'\()3t
{ .oLV\'HAR
try{ bi",DKU{l
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HOCj* O4
int nCount = input.readInt(); $?k]KD
nStartPos = new long[nCount]; QX<x2U
nEndPos = new long[nCount]; [.Kp/,JY
for(int i=0;i<nStartPos.length;i++) 1kvs2
{ #,6T.O
nStartPos = input.readLong(); u-:3C<&>
nEndPos = input.readLong(); ; Ad5Jk
} 5F ^VvzNn
input.close(); Ks6\lpr
} /Yg&:@L
catch(IOException e){e.printStackTrace ();} S++~w9}
catch(Exception e){e.printStackTrace ();} 9^8OIv?m8
} <;~u@^>
{i8zM6eC
)$df6sq
private void processErrorCode(int nErrorCode) W-&V:S{<
{ `JPkho
System.err.println("Error Code : " + nErrorCode); f^u-Myk
} GQCdB>
Z(Y:
d(ypFd9z
//停止文件下载 T{f$S
public void siteStop() Qe ip h
{ J,u-)9yBA<
bStop = true; fG$LqzyqlK
for(int i=0;i<nStartPos.length;i++) ~gMt U
fileSplitterFetch.splitterStop(); rJCb8x+5a
gM=:80
!3mt<i]a"
} #C?M-
} 6W=V8
//负责部分文件的抓取 2E!~RjxSY
**FileSplitterFetch.java /}L2LMIm
*/ PcU~1m1
package NetFox; Q3&q%n|<
v}V[sIs}
324XoMO
import java.io.*; {)!>e
import java.net.*; S5y.H
GbL1<P$V
+)e|>
public class FileSplitterFetch extends Thread { $$&.}}.,
*`Vmncv3
@v#P u_
String sURL; //File URL ^ W?cuJ8
long nStartPos; //File Snippet Start Position 3)\fZYu)
long nEndPos; //File Snippet End Position X|eZpIA45
int nThreadID; //Thread's ID )S2yU<6oOt
boolean bDownOver = false; //Downing is over s:"Sbml
boolean bStop = false; //Stop identical xSK#ovH2
FileAccessI fileAccessI = null; //File Access interface W [K.|8ho
Xw!\,"{s
@&WHX#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Jut&J]{h
{ u YT$$'S
this.sURL = sURL; G7al@
this.nStartPos = nStart; JDE_*xaUV
this.nEndPos = nEnd; VLkAsM5}%
nThreadID = id; [{BY$"b#:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bD:0k.`
} g]2L[4
Q^rR}Ws
M%!;5
public void run() W_Y8)KxG:L
{ p T8?z
while(nStartPos < nEndPos && !bStop) !#O[RS
{ uy3<2L#.
yivu|q
|9c~kTjK
try{ VoZ{I{>|
URL url = new URL(sURL); $P0q!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tn5
httpConnection.setRequestProperty("User-Agent","NetFox"); Wa<<"x$
String sProperty = "bytes="+nStartPos+"-"; !ou#g5Q@z
httpConnection.setRequestProperty("RANGE",sProperty); r%ES#\L6+|
Utility.log(sProperty); CG=c@-"n/
K\F0nToJ.
6- i.*!I 8
InputStream input = httpConnection.getInputStream(); _f^KP@^j
//logResponseHead(httpConnection); r8Pd}ptPU
JL= cIH8
chE!,gik
byte[] b = new byte[1024]; hb5K"9Y
int nRead; ;J5z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) x^f)I|t
{ p1Zb&:+
nStartPos += fileAccessI.write(b,0,nRead); GYaP"3Lu
//if(nThreadID == 1) V;XKvH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nG!<wlY14P
} 2Kz+COP+
xZ9:9/Vg
n_e'n|T
Utility.log("Thread " + nThreadID + " is over!"); ?W'p&(;
bDownOver = true; 3N+lWuE}K
//nPos = fileAccessI.write (b,0,nRead); 7R2O[=Szq
} ,94<j,"
catch(Exception e){e.printStackTrace ();} zzQWHg]/
} Lqj Qv$
} M`Er&nQs
G:1'}RC :
Z nc(Q
//打印回应的头信息 @dDeOnF
public void logResponseHead(HttpURLConnection con) MePD:;mm^
{ kW g.-$pp
for(int i=1;;i++) WKEb '^
{ w6% Q"%rp
String header=con.getHeaderFieldKey(i); m.e]tTe
if(header!=null) \WCQ>c?~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v~P,OP("c
Utility.log(header+" : "+con.getHeaderField(header)); o|(5Sr&H
else Dsg>~J'
break; 3yZmW$E.
} d,"LZ>hNY*
} F1t(P 8
z*eBjHbF
smQ^(S^
public void splitterStop() f&^(f1WO
{ iEr,ly
bStop = true; k&]nF,f
} )u)=@@k21
_/s"VYFZ
hArY$T&MB
} o%$.8)B9F
BX@Iq
Tu#< {'1$
/* g7*)|FOb
**FileAccess.java yw3"jdcl
*//文件访问(定位，写) Eah6"j!B8n
package NetFox; OU[<\d
import java.io.*; *U?O4E9
NB"S,\M0
V2YK T,5
public class FileAccessI implements Serializable{ o\IMYT
UNdD2Fd9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %@/^UE:
RandomAccessFile oSavedFile; 0lfK} a
long nPos; :d36oiHKu
ggr
~C.*Vc?|
public FileAccessI() throws IOException }]?Si6_ZZ
{ AlSO
this("",0); VM"cpC_8
} tli.g
bLgH3[{
^QB[;g.O
public FileAccessI(String sName,long nPos) throws IOException D6sw"V#
{ k*.]*]
oSavedFile = new RandomAccessFile(sName,"rw"); hRcb}>pr
this.nPos = nPos; c?p^!zG
oSavedFile.seek(nPos); g,ZA\R~
} yBIlwN`kB
xvr5$x|h
2ej7Ql_@c
public synchronized int write(byte[] b,int nStart,int nLen) <qCa9@Ea
{ <AHpk5Sn{
int n = -1; uy'ghF
try{ pm&THd
oSavedFile.write(b,nStart,nLen); lo1Ui`V
n = nLen; gg;r;3u
} E h%61/
catch(IOException e) 5jdZC(q5a
{ ^[L(kHOGzk
e.printStackTrace (); J~Xv R
} ]$ew 5%
[uq>b|`RG
29R-Up!SVN
return n; )*|/5wW1
} QFyL2Xes/
8!g `bC#%
I$Nh|eM
} bQAznd0
i%glQT
&c`-/8c
/* dj|5'<l2
**SiteInfoBean.java ^?69|,
*/ BG{f)2F\
package NetFox; 'm%{Rz>j
R;& >PFmq
8#I>`z^F
public class SiteInfoBean { T:|/ux3
A]1Nm3@
W+nu=iQ!
private String sSiteURL; //Site's URL J3Mb]X)_}
private String sFilePath; //Saved File's Path /YKd [RQ
private String sFileName; //Saved File's Name d1/emwH
private int nSplitter; //Count of Splited Downloading File D)_ C@*q
Rd?}<L
>%JPgr/ 8
public SiteInfoBean() Otn,UoeeB
{//nSplitter的缺省值为5 ?I.9?cQXZ
//default value of nSplitter is 5 4DXbeQs:
this("","","",5); CU$khz"
} WKf<% E$
)fH Q7
-!\3;/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \?:L>-&h8
{ h\m35'v!
sSiteURL= sURL; b^Hrzn
sFilePath = sPath; idmU.`
sFileName = sName; QbU5FPiN
this.nSplitter = nSpiltter; B( [x8A]
&}ZmT>q`$
^}3^|jF
} BT_]=\zi
e4X df>B
yr]ja-Y
public String getSSiteURL() O--p)\
{ wak26W>I3
return sSiteURL; x_PO;
} q:{#kv8
St=nf\P&F
;%|im?
public void setSSiteURL(String value) ;D5>iek5
{ }E`Y.= S
sSiteURL = value; 3f|}p{3
} b`0tfXzS5
L aTcBcI
tobE3Od4
public String getSFilePath() pA7-B>Y
{ AXfU$~
return sFilePath; :,BAw ,
} 2:+8]b3i
N'^>pSc4W|
5Z=4%P*I
public void setSFilePath(String value) Z:b?^u4.
{ 570Xk\R@M
sFilePath = value; {%jAp11y+O
} 9rB3h`AVF
I?KN7(9u?
~W'DEpq_
public String getSFileName() P\7DA4]
{ 5f0M{J,KC
return sFileName; <H[w0Z$
} jzvK;*N
$Dg-;I
l![M,8
public void setSFileName(String value) ~NGM6+9
{ yCX5 5:
sFileName = value; AbU`wr/h 4
} "tCI_ Zi;
#-az]s|N
p^l#Wq5
public int getNSplitter() QE<Z@/V*a
{ whI{?NP
return nSplitter; .j6udiv5
} 2j\_svw'
[V}vd@*k
:4AQhn^;"
public void setNSplitter(int nCount) ^0,}y]5p
{ aRd~T6I
nSplitter = nCount; 6]4~]!
} +cpb!YEAb
} 1nVQYqT_
2g(_Kdj*{
qLR;:$]Q&8
/* +in)(a.
**Utility.java ?pL|eS7
*/ +Z#=z,.^
package NetFox; K5>3
eAHY/Y!
5!0iK9O
public class Utility { /08FV|tX)
2:LUB)&i
>}k*!J|
public Utility() !&)X5oJ
{ " <bjS
KdNo'*;U]_
-:}vf?
} VPCI5mS_
2"0VXtv6
//线程睡眠 gI:g/ R
public static void sleep(int nSecond) !G%!zNA S
{ bGh&@&dHr
try{ 'r'=%u$1C
Thread.sleep(nSecond); &oL"AJU
} xvGYd,dlK
catch(Exception e) s/1r{;q
{ 88Pt"[{1
e.printStackTrace (); UMcM&yu-
} bR`5g
} +V=<vT
Aez2n(yac
//日志 %Z;RY5
public static void log(String sMsg) EeaJUK]z9
{ QPy h.9:N
System.err.println(sMsg); nC:T0OJv
} ^Ks1[xc*`
@`.4"*@M
Rsx6vF8]5
public static void log(int sMsg) &_)P)L
{ UG vIHm
System.err.println(sMsg); R ENCk(
} [gzaOP`f
} bbL\xq^
s'O%@/;J
@= <{_p
/* l,n_G/\
**TestMethod.java Vmz#u1gGT6
*/ y)r`<B
package NetFox; o*T?f)_[p
.M6.]H
GTs,?t16/
public class TestMethod { I!zoo[/)%
x1=`Z@^
U<6)CW1;
public TestMethod() GzEw~JAs
{ ///xx/weblogic60b2_win.exe l6zAMyau5
try{ R;"$PHD
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {[uhIJD3g6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;&lXgC^*
SiteFileFetch fileFetch = new SiteFileFetch(bean); eKP>}`
fileFetch.start(); 1^IMoC7$#
} c coi
catch(Exception e){e.printStackTrace ();} ~HY)$Yp;
e_-g|ukC
]W3u~T*
} l@4pZkdq
&UDbH* !4=
G-CL \G\n
public static void main(String[] args) D(z#)oDr
{ U& GPede
new TestMethod(); mmQC9nZ
} tFcQ.1
} Q_T,=y
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