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)); %l8*t$8
} 4#@W;'
for(int i=0;i<nEndPos.length-1;i++) UKKSc>D1
{ sw41wj
nEndPos = nStartPos[i+1]; UBhciZ
} Y3P.|
nEndPos[nEndPos.length-1] = nFileLength; ];pf
} p- "Z'$A`
} Vedyy\TU
$*AC>i\
FI1THzW4J
//启动子线程 GJIWG&C03
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %_b^!FR
for(int i=0;i<nStartPos.length;i++) {*?sVAvj
{ @q> ktE_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V\@jC\-5Vt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), N;Z`%&
nStartPos,nEndPos,i); *?^Z)C>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Sg.+`xww3
fileSplitterFetch.start(); }xkLD!
} ?~aZ#%*i8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $Wr\[P:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); tLD~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *t#s$Ga
nEndPos = " + nFileLength); poXLy/K
// fileSplitterFetch[nPos.length-1].start(); @%EE0)IA
XOysgX0g
5!'R'x5e
//等待子线程结束 HDF!`
//int count = 0; o%Be0~n'
//是否结束while循环 AezvBY0'`z
boolean breakWhile = false; ~|CJsD/
F-BJe]
N+CXOI=6x
while(!bStop) HYjMNj0
{ b&lN%+%}
write_nPos(); f{y]
Utility.sleep(500); /OQK/ t63
breakWhile = true; :vc[/<
<i_> y~v`
x],8yR)R
for(int i=0;i<nStartPos.length;i++) [!1)mR
{ Fw_ (q!
if(!fileSplitterFetch.bDownOver) KqM!!
{ -A/ds1=;
breakWhile = false; K<@[_W+
break; zVM4BT(
} le7 `uz!%
} ?xtt7*'D
if(breakWhile) kAZC"qM%i
break; R*s* +I
V#ndyUM;
kCima/+_
//count++; 8G0
//if(count>4) .MDYGWKt
// siteStop(); nE/=:{~Ws
} uy/y wm/?=
.A3DFm3t
gw_|C|!P
System.err.println("文件下载结束！"); p=!#],[
} BRQ"A,
catch(Exception e){e.printStackTrace ();} aB6Ye/Io
} 1<xcMn0et
KxO/]
)46 0Ed
//获得文件长度 rkxW UDl
public long getFileSize() :{[<g](
{ u5Qp/ag?N
int nFileLength = -1; `S"W8_m
try{ #v.L$7O
URL url = new URL(siteInfoBean.getSSiteURL()); \'n$&PFe
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X'cf&>h
httpConnection.setRequestProperty("User-Agent","NetFox"); r%0pQEl
[NYj.#,oR
IE&_!ce
int responseCode=httpConnection.getResponseCode(); JXpoCCe
if(responseCode>=400) 3c c1EQ9
{ f?,-j>[.=f
processErrorCode(responseCode); ~O \}/I28
return -2; //-2 represent access is error ?n!lUr$:y
} f#@S*^%V$
;aq`N}d
vG Y!4@[
String sHeader; Y4QLs^IdB
p3g4p
Xo2^N2I
for(int i=1;;i++) hlX>K
{ ($c`s8mp
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9160L qY
//Utility.log(in.readLine()); r=h8oUNEJ*
sHeader=httpConnection.getHeaderFieldKey(i); cp$.,V
if(sHeader!=null) :@.C4oq
{ :~yzDk\I"-
if(sHeader.equals("Content-Length")) CE)*qFs
{ H{ZLk,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L>SZgmV+
break; 5v"Y\k+1
} _-n Y2)
} Z;hyi'rPJ
else A:/}`
break; hQXxG/yFm
} /T,zZ9=
} zVdKYs i^
catch(IOException e){e.printStackTrace ();} VsEGX@;tO
catch(Exception e){e.printStackTrace ();} 4<u;a46Z#M
DlDB=N0@S
MFv Si
Utility.log(nFileLength); VSh!4z1
bZiyapM
+4Q[N;[+*
return nFileLength; XTV0Le\f
} B$ui:R/ t
;TtaH
XJUEwX
//保存下载信息（文件指针位置） b7bSTFZxC
private void write_nPos() bZ/ hgqS
{ oew|23Ytb
try{ qmEoqU
output = new DataOutputStream(new FileOutputStream(tmpFile)); z OtkC3hY
output.writeInt(nStartPos.length); f3!n$lj
for(int i=0;i<nStartPos.length;i++) h6g:(3t6m
{ L/BHexOB
// output.writeLong(nPos); kfXS_\@iW1
output.writeLong(fileSplitterFetch.nStartPos); >rKhlUD
output.writeLong(fileSplitterFetch.nEndPos); 0C]4~F x~
} V7:\q^$
output.close(); r&SO:#rOSM
} I:F <vE
catch(IOException e){e.printStackTrace ();} Twx{' S
catch(Exception e){e.printStackTrace ();} H<,bq*@
} Uj,g]e8e
*6XRjq^#
EY~7oNfc`R
//读取保存的下载信息（文件指针位置） ! tGiTzzp
private void read_nPos() UxeL cUP
{ y1iX!m~)
try{ ?;^5ghY$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (k8Z=/N~
int nCount = input.readInt(); /_q#ah
nStartPos = new long[nCount]; M|k&TTV
nEndPos = new long[nCount]; hfg O
for(int i=0;i<nStartPos.length;i++) (etUEb^}T
{ 45)D+
nStartPos = input.readLong(); };rm3;~ eg
nEndPos = input.readLong(); )6=gooe]
} wlrIgn%
input.close(); 7H%_sw5S.
} uJY.5w
catch(IOException e){e.printStackTrace ();} S6GMUaR
catch(Exception e){e.printStackTrace ();} Wab.|\c
} [t{](-
.a:Z!KF
VD/&%O8n
private void processErrorCode(int nErrorCode) 9<l-NU9 _
{ 088C|
System.err.println("Error Code : " + nErrorCode); Jn*Nao_)
} 9:-T@u
0R|K0XH#$
Z(HZB
//停止文件下载 D-pX<0-y
public void siteStop() >! oF0R_<
{ :G}DAUFN
bStop = true; 4[1k\
for(int i=0;i<nStartPos.length;i++) 333u]
fileSplitterFetch.splitterStop(); %}h`+L
4{Udz!
9#Y2`pT
} ;g9%&
} E?Cj/o
//负责部分文件的抓取 n+?-�
**FileSplitterFetch.java :_Fxy5}
*/ Hd0Xx}3&
package NetFox; IBET'!j4"
ufPCx|x~
>)^NJ2Fd
import java.io.*; <Y>3
import java.net.*; ,eXFN?CB
W`x)=y]Z
1~@|eWr|
public class FileSplitterFetch extends Thread { RM,'o[%
>rw"Rd'
OR;&TbWF(R
String sURL; //File URL _R74/|
long nStartPos; //File Snippet Start Position p+[}Hxx=
long nEndPos; //File Snippet End Position >A($8=+#x
int nThreadID; //Thread's ID U Du~2%
boolean bDownOver = false; //Downing is over t8vc@of$c,
boolean bStop = false; //Stop identical ;&kn"b}G;
FileAccessI fileAccessI = null; //File Access interface iNJAZ6@+
6vobta^w
\Yq0 zVol
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "0-y*1/m
{ qlUzr.^-
this.sURL = sURL; B+46.bIH
this.nStartPos = nStart; ! =WcF5
this.nEndPos = nEnd; h<Wg3o
nThreadID = id; ,QvYTJ{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F7T E|LZ
} TatMf;?h&
KO&:06V{
H&bh<KPMh
public void run() 7/"@yVBW
{ 6m[9b*s7
while(nStartPos < nEndPos && !bStop) P}@*Z>j:#
{ a#y{pT2 b
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s}(X]Gx1
try{ El (/em
URL url = new URL(sURL); 8l23%iWxe
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JZ=5Bpw
httpConnection.setRequestProperty("User-Agent","NetFox"); )%VCzye*{
String sProperty = "bytes="+nStartPos+"-"; GV8)Kor%
httpConnection.setRequestProperty("RANGE",sProperty); {eR9 ;2!
Utility.log(sProperty); {|6z+vR
v[&'k\
,I`_F,
InputStream input = httpConnection.getInputStream(); m*oc)x7'
//logResponseHead(httpConnection); rzu s
tpYa?ZCM
eYEc^nC,c)
byte[] b = new byte[1024]; Hku=pr3Gn
int nRead; ZEGd4_ux
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /{X_ .fv<v
{ 85z;Zt0{
nStartPos += fileAccessI.write(b,0,nRead); cZi[(K
//if(nThreadID == 1) w>vH8f
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KlUqoJ;"
} d#\W hRE
A[H;WKn0
C9jbv/c
Utility.log("Thread " + nThreadID + " is over!"); 0H[LS
bDownOver = true; pjN:&#Y]
//nPos = fileAccessI.write (b,0,nRead); 5pJ*1pfeo
} L~eAQR
catch(Exception e){e.printStackTrace ();} bUs|t
} t5)J;0/
} TyOH`5D
#DUh(:E'`
|C D}<r(N
//打印回应的头信息 _M5Xk?e=
public void logResponseHead(HttpURLConnection con) *]x_,:R6Ow
{ a)S7}0|R
for(int i=1;;i++) C).2gQ G
{ ce'TYkPM
String header=con.getHeaderFieldKey(i); 0JXqhc9'
if(header!=null) TpP8=8_Lh
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <AUWby,"
Utility.log(header+" : "+con.getHeaderField(header)); /s[DI;M$o
else 'ere!:GJD
break; ^,V[nfQR
} xvDI 4x&
} uvB1VV4
Y=Hz;Ni
xR908+>5
public void splitterStop() uRQ_'l
{ o:UXPAj
bStop = true; `^##b6jH
} te'*<HM
|4Ha?W
C4NRDwU|.
} If'2rE7J
n93zD*;5
6[?}6gQ
/* sX:lE^)-z
**FileAccess.java XnXb&@Y
*//文件访问(定位，写) !Iq{ 5:
package NetFox; &1GUi{I
import java.io.*; |(ocDmd
Z;b+>2oL
iP "EA8
public class FileAccessI implements Serializable{ AyTx'u
m;/i<:`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FFe)e>bH
RandomAccessFile oSavedFile; SLoo:)
long nPos; 6c<ezEJ
Q6^x8
6fwY$K\X
public FileAccessI() throws IOException T=\!2gt
{ )^ <3\e
this("",0); ?63&g{vA
} \##`pa(8
+v15[^F
R]QpMj%o
public FileAccessI(String sName,long nPos) throws IOException nY^Nbh0
{ d 4O
oSavedFile = new RandomAccessFile(sName,"rw"); ;[6&0!N\
this.nPos = nPos; ($WE=biZ&
oSavedFile.seek(nPos); qY# d+F,t
} nb+m.X
<k]qH-v4
8(xw?|D7
public synchronized int write(byte[] b,int nStart,int nLen) i2`0|8mw'
{ ;V.vfar
int n = -1; r4;Bu<PQN1
try{ !T'X 'Q
oSavedFile.write(b,nStart,nLen); nq;#_Rkr
n = nLen; X~RH^VYv
} z\.1>/Z=
catch(IOException e) nyhMnp#<
{ tWD|qg_
e.printStackTrace (); 9?`RR/w
} ,{{SI
dr})-R
o&-L0]i|
return n; T-8J
} 77Q}=80GU;
(0jr;jv
#":a6%0Q
} JJf<*j^G
(5`T+pAsV
N z~"vi(t
/* AcC8)xRpk4
**SiteInfoBean.java O&$0&dhc
*/ Iql5T#K+
package NetFox; 0kLEBoOh
vA-PR&
3] 76fF\^[
public class SiteInfoBean { {XnPx?V
((MLM3zJ
PXEKV0y
private String sSiteURL; //Site's URL V5MO}
private String sFilePath; //Saved File's Path 6Rz[?-mkLO
private String sFileName; //Saved File's Name GGE[{Gb9
private int nSplitter; //Count of Splited Downloading File _#'9kx|)
oR %agvc^^
i\p:#'zk5
public SiteInfoBean() Q4K+*Fi}
{//nSplitter的缺省值为5 {Y_Nj`#BT
//default value of nSplitter is 5 (9GbG"
this("","","",5); &!1}`4$[T
} ;KcFy@ 6q5
?`P2'i<b
K{L.ZH>7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Z?1OdoT-
{ "#S>I8d
sSiteURL= sURL; e@jfIF0=}
sFilePath = sPath; _D-Riu>#J
sFileName = sName; m6U8)!)T
this.nSplitter = nSpiltter; s~$zWx@v
E`)Qs[?Gk
dlD}Ub
} :p-Y7CSSu
iJP{|-h
Z"tQpJg
public String getSSiteURL() qrDcL>Hrn
{ T[2}p=<%
return sSiteURL; )%mAZk-*;^
} 3{3/: 7
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.~`Y)PON
public void setSSiteURL(String value) !F7:i
{ )N)ljA3]
sSiteURL = value; rYGRz#:~+
} hKksVi
g42T#p8^
4vqNule
public String getSFilePath() _A-V@%3
{ ~3=2=Uf
return sFilePath; /DU*M,
} kxo.v|)8
\cZfg%PN
8p=>?wG
public void setSFilePath(String value) iz`jDa Q|1
{ V^En8
sFilePath = value; cU+>|'f&
} 93D \R
kZ[mM'u#
]^@0+!
public String getSFileName() e@j8T gI)
{ I,j3bC
return sFileName; hTw}X.<4
} %dmfBf Ev
Uu5C%9^s
pULsGb
public void setSFileName(String value) |s|/]aD}o
{ e2Jp'93o'
sFileName = value; 8^X]z|[d2
} },PBqWe
{!=2<-Aq
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public int getNSplitter() ragSy8M
{ Dl\d_:+
return nSplitter; Dh`=ydI5
} 3!Bj{;A
xOIg|2^8
BKA]G)G7u!
public void setNSplitter(int nCount) XGIpUz
{ wLMvC{5
nSplitter = nCount; bi,mM,N/
} mP!N<K
} 0N VI+Z$
:bv|Ah
q6&67u0
/* -eL'KO5'
**Utility.java /f&By p
*/ b *9-}g:
package NetFox; `a'`$'j
k1iLnza%
('d{t:TsY
public class Utility { b42QBTeg
XRa#21pQ
T} 8CfG_j
public Utility() <gcmsiB|
{ o)!m$Q~v
owMmCR
oD,C<[(p
} UTX](:TC
wlVvxX3%
//线程睡眠 BWEv1' v
public static void sleep(int nSecond) sVoR?peQ
{ <[9?Rj@
try{ (nz}J)T&
Thread.sleep(nSecond); :c<*%*e
} SG`)PW?
catch(Exception e) #eLN1q&Z
{ OPiaG!3<
e.printStackTrace (); M.[wKGX(
} K;C_Z/<%
} P;c0L;/
(H-cDsh;c
//日志 {]["6V6W
public static void log(String sMsg) *(nJX.7
{ 5H!%0LrJg=
System.err.println(sMsg); WRM$DA
} \n(ROf^'
wA",SBGX
y.ql#eQ,
public static void log(int sMsg) .C?GW1[c~@
{ >)y$mc6
System.err.println(sMsg); YkI9d&ib+
} 4k$0CbHx0
} 97]4 :Zv
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`EVg'?pl
/* H9E(\)@
**TestMethod.java R8uj3!3^
*/ ~#t*pOC5BR
package NetFox; kF2Qv.5!
j"6:A
>KHp-|0pv
public class TestMethod { ,-:a?#f>
P57GqT
EW9b*r7./
public TestMethod() g? I!OG
{ ///xx/weblogic60b2_win.exe ?OO%5PSen
try{ ^Po,(iIn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )-#i8?y3C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `:gYXeR
SiteFileFetch fileFetch = new SiteFileFetch(bean); yU!GS-
fileFetch.start(); {\Ys@FF
} @E(P9zQ/zy
catch(Exception e){e.printStackTrace ();} V" }*"P-%
_<2RYXBC
}Az'Zu4 =
} z \^
Se/ss!If
N-Z^G<[q.
public static void main(String[] args) ^Rk^XQCh
{ %GVN4y&
new TestMethod(); ) H+d.Y
} ETg{yBsp
} HSC6;~U
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