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)); LPq*ZZK
} ?r -\%_J_(
for(int i=0;i<nEndPos.length-1;i++) N5q}::Odc
{ #Acon7Rp
nEndPos = nStartPos[i+1]; (TT3(|v
} :DOr!PNA
nEndPos[nEndPos.length-1] = nFileLength; o9KyAP$2
} bc3|;O
} avu*>SB
Ij;==f~G
x !#Ma
//启动子线程 ]k[Q]:q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8BYIxHHz
for(int i=0;i<nStartPos.length;i++) .DgoOo%?"
{ e={k.y}x}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7.wR"1p#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wFK:Dp_^
nStartPos,nEndPos,i); MuDFdbtR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); io1S9a(y
fileSplitterFetch.start(); \]Y\P~n
} l 8O"w&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :3111}>c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~pHJ0g:t
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h|J;6Sm@
nEndPos = " + nFileLength); ]4Nvh\/P9
// fileSplitterFetch[nPos.length-1].start(); ?8Hn{3X
]%gp?9wy
fkdf~Vb
//等待子线程结束 33=Mm/<m$P
//int count = 0; x2 w8zT6M
//是否结束while循环 R'*<A3^
boolean breakWhile = false; ^-gfib|VGe
_v1bTg"?
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while(!bStop) Zij"/gx\
{ 7!O^;]+,
write_nPos(); Nc G,0K
Utility.sleep(500); KotPV
breakWhile = true; ggerh#
E)KB@f<g*
3x04JE3!
for(int i=0;i<nStartPos.length;i++) 8!Wfd)4=,F
{ Of1IdE6~
if(!fileSplitterFetch.bDownOver) lr9=OlH
{ Wr]O
breakWhile = false; 4a\n4KO X
break; xCR; K]!
} ]XmQ]Yit
} VYL@RL'
if(breakWhile) 6P0y-%[Gk
break; cDfx)sL
LiiK3!^i
4st~3,lR$
//count++; t{+M|Y
//if(count>4) o)0C-yO0qf
// siteStop(); f&6w;T=
} 6{5q@9F
D~cW ]2
=YWT|%^uX
System.err.println("文件下载结束！"); A{4Dzm!
} aML#Z|n
catch(Exception e){e.printStackTrace ();} ' be P
} u8|@|t
C>AcK#-x,{
bBA$}bv
//获得文件长度 d/l,C4p
public long getFileSize() 6,B-:{{e"
{ ?lF mXZy`
int nFileLength = -1; \|v`l{
try{ V@B7P{gH
URL url = new URL(siteInfoBean.getSSiteURL()); `Ac:f5a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +T-@5v[
httpConnection.setRequestProperty("User-Agent","NetFox"); YKc>6)j
R78!x*U}
3 t/ R2M
int responseCode=httpConnection.getResponseCode(); 6hp{,8|D"m
if(responseCode>=400) I|H,)!Z
{ 5i|s>pD4z1
processErrorCode(responseCode); ):/,w!1
return -2; //-2 represent access is error ~q*i;*
} PoJmW^:}
`tX@8|
3voW
String sHeader; q5%2WM]6
Q6u{@$(/N
a[q84[OQ
for(int i=1;;i++) D)y{{g*Lnm
{ PXa5g5!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s\6N }[s
//Utility.log(in.readLine()); +yGY785b
sHeader=httpConnection.getHeaderFieldKey(i); p=2zS.
if(sHeader!=null) =D{B}=D\IM
{ }I\-HP8!gv
if(sHeader.equals("Content-Length")) :=y0'f V(@
{ Dzo{PstM%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e"*BHvy F
break; R_7 6W&
} S)+CTVVE
} tL1P<1j_
else vuXS/ d
break; HF]EU!OT
} j]>=1Rd0b(
} >o#ERNf
catch(IOException e){e.printStackTrace ();} h(_P9E[g
catch(Exception e){e.printStackTrace ();} \WcB9
[ne" T
+)zDA:2Wa"
Utility.log(nFileLength); I|Z/`9T
Np$z%ewK.
^,+nef?=
return nFileLength; 6nc0=~='$
} ^/k,
z9 O~W5-U
O)OUy
//保存下载信息（文件指针位置） 21ViHV
private void write_nPos() 7 %3<~'v[
{ *_PPrx5
try{ m#*h{U$
output = new DataOutputStream(new FileOutputStream(tmpFile)); \<X2ns@Tf
output.writeInt(nStartPos.length); vm|!{5l:=y
for(int i=0;i<nStartPos.length;i++) -xz|ayn
{ _r]nJEF5
// output.writeLong(nPos); o!=WFAi[pX
output.writeLong(fileSplitterFetch.nStartPos); 3B;}j/h2
output.writeLong(fileSplitterFetch.nEndPos); 3I]Fdp)'
} '[Xl>Z[
output.close(); 0potz]}
} \04mLIJr9
catch(IOException e){e.printStackTrace ();} |gW
catch(Exception e){e.printStackTrace ();} (|dPeix|
} <~N%W#z/
Vg{Zv4+t
p!}ZdX[u
//读取保存的下载信息（文件指针位置） 7u::5W-q
private void read_nPos() eHUg-\dy
{ 4#_$@ r
try{ R5~gH6K|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); '#A:.P
int nCount = input.readInt(); #I;D
nStartPos = new long[nCount]; qcYNtEs*c
nEndPos = new long[nCount]; y+A{Y
for(int i=0;i<nStartPos.length;i++) tfA}`*$s
{ %kq ^]S2O
nStartPos = input.readLong(); yc[(lq.^n
nEndPos = input.readLong(); g,=^'D
} b~*i91)\
input.close(); F?cq'd
} 5/ * >v
catch(IOException e){e.printStackTrace ();} VRF6g|0;
catch(Exception e){e.printStackTrace ();} t7bqk!6hM\
} ` 5#hjLe
~p\n&{P0
rGQ5l1</
private void processErrorCode(int nErrorCode) @;;G88=
{ )&,K94
System.err.println("Error Code : " + nErrorCode); vOe0}cR
} =*O=E@]
f TO+ZTRqf
Tm_8<$ 7
//停止文件下载 ;%Q&hwj
public void siteStop() ' S,2
{ &{ZSE^
bStop = true; 4jGLAor|
for(int i=0;i<nStartPos.length;i++) U(*yL-
fileSplitterFetch.splitterStop(); csDQva\
w12}Rn8
m2O&2[g
} UOt8Q0)}
} '_0
//负责部分文件的抓取 5ITq?%{M
**FileSplitterFetch.java Yb6q))Y
*/ ZdH1nX(Yh3
package NetFox; /c#l9&,
! Mo`^t
LG&5VxT=,<
import java.io.*; |` "?
import java.net.*; 2m"_z
\ha-"Aqze3
)7Ixz1I9g
public class FileSplitterFetch extends Thread { W5Zqgsy($F
Xa,\EEmQ
Kam]Mn'
String sURL; //File URL Q'K$L9q
long nStartPos; //File Snippet Start Position Ly>OLI0x_
long nEndPos; //File Snippet End Position 41yOXy ;~l
int nThreadID; //Thread's ID [!~}S
boolean bDownOver = false; //Downing is over `WnQ
boolean bStop = false; //Stop identical smup,RNZRX
FileAccessI fileAccessI = null; //File Access interface 6D/tK|
x8\<qh*:
h e&V# #
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8+&JQ"UaB
{ Hb!6ZEmN%
this.sURL = sURL; 8TPN#"
this.nStartPos = nStart; zCV7%,H~
this.nEndPos = nEnd; Qxt@V
nThreadID = id; g5Td("&n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /:p8I6;
} :1;Q(9:v
%K1")s
u7].}60.'
public void run() p/*"4-S
{ _a5(s2wq+
while(nStartPos < nEndPos && !bStop) ,2,5Odrz
{ x=*L-
e&1\'Zq?>
Mu2`ODe]
try{ OCK>%o$[
URL url = new URL(sURL); pM2a(\K,k^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m@\ZHbq
httpConnection.setRequestProperty("User-Agent","NetFox"); re`t ]gzb
String sProperty = "bytes="+nStartPos+"-"; <3Gqv9Y&
httpConnection.setRequestProperty("RANGE",sProperty); :=fvZAWD
Utility.log(sProperty); iM5vrz`n
9Cvn6{
X+l'bp]Ry
InputStream input = httpConnection.getInputStream(); :E'P7A
//logResponseHead(httpConnection); O+"ac /r
62\&RRB i
XYfv(y
byte[] b = new byte[1024]; %|+E48
int nRead; @cv{rr
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T)SbHp Y
{ &&7r+.Y
nStartPos += fileAccessI.write(b,0,nRead); Oy_c
//if(nThreadID == 1) j@| `f((4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Eju~}:Lo
} WG5W0T_
fdv`7u+}a
BsLG^f
Utility.log("Thread " + nThreadID + " is over!"); f/y`
bDownOver = true; DWm SC}{.
//nPos = fileAccessI.write (b,0,nRead); n:4uA`Vg
} Z cpmquf8L
catch(Exception e){e.printStackTrace ();} /3B6Mtb
} 1%`7.;!i
} |B^G:7c
Vmi{X b]<
~uj;qq
//打印回应的头信息 ln<]-)&C
public void logResponseHead(HttpURLConnection con) 6rX_-Mm6w
{ s>%Pd7:
for(int i=1;;i++) T):SGW
{ y%cO#P@
String header=con.getHeaderFieldKey(i); qf8[!5GM
if(header!=null) .CbGDZ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1-VT}J(
Utility.log(header+" : "+con.getHeaderField(header)); L?RF;jf
else nE|@IGH
break; Em^(
} yL1CZ_
} 2]WE({P
mT.e>/pa
+ WDq=S
public void splitterStop() [j9E pi(
{ 0KvVw rWJ
bStop = true; i8PuC^]
} N1x@-/xa|
d,cN(
'&yeQ
} jbmTmh1q
Y(6Sp'0
..<3%fL3
/* XL5Es:"+?S
**FileAccess.java 0 f/.>1M=
*//文件访问(定位，写) %2l7Hmp4H
package NetFox; cAuY4RV
import java.io.*; K@:m/Z}|4
HY}j!X
I+;-p]~
public class FileAccessI implements Serializable{ L%cVykWY"
vqNsZ 8|`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5#2F1NX
RandomAccessFile oSavedFile; jC, FG'P
long nPos; G|u3UhyB
BNucc']
%NARyz
public FileAccessI() throws IOException Qt+:4{He
{ z/]q)`G
this("",0); 0$P/jt
} buMqF-j
Q^_/By@
C"w {\ &R
public FileAccessI(String sName,long nPos) throws IOException Ru\_dr2yI}
{ oC|WBS
oSavedFile = new RandomAccessFile(sName,"rw"); \%A%s*1
this.nPos = nPos; xN0*8
oSavedFile.seek(nPos); V H^AcO
} A(d5G^
ktH8as^54!
g:#dl\k
public synchronized int write(byte[] b,int nStart,int nLen) !<\Br
{ v"Jgw;3
int n = -1; 5OP`c<
try{ lWZuXb,G
oSavedFile.write(b,nStart,nLen); #D%ygh=
n = nLen; #-#NqX:
} Qx`~g,wk8
catch(IOException e) !|G(Yg7C
{ (lH,JX`$a
e.printStackTrace (); USPTpjt8R
} ANMg
~H /2R
+M\8>/0oA
return n; k9si|'
} e [0w5)X
Ff4*IOZ}(
j tA*pL'/V
} >'=MH2;
%{5n1w
HgRwiIt
/* gn1(4 o
**SiteInfoBean.java l=P'B @,
*/ JBX[bx52<r
package NetFox; ;?L\Fz(<
3:CO{=`\7B
W?RE'QV8
public class SiteInfoBean { C2F0tr|
~oD8Rnf
oduDA:
private String sSiteURL; //Site's URL zY9H%
private String sFilePath; //Saved File's Path 0Bolv_e
private String sFileName; //Saved File's Name XSRdqU>Aun
private int nSplitter; //Count of Splited Downloading File !]?$f=
P\R27Jd
g@v s*xE
public SiteInfoBean() fP-|+TyO
{//nSplitter的缺省值为5 dE=Ue#1U@5
//default value of nSplitter is 5 )ZR+lX}
this("","","",5); %@J1]E;
} "5|Lz)=
#Z!b G?="
uQCo6"e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =[tSd)D,y
{ woOy*)@
sSiteURL= sURL; NYB[Zyp
sFilePath = sPath; {U11^w1"3
sFileName = sName; )M<vAUF
this.nSplitter = nSpiltter; x8#ODuH
f"5g>[1
wsfd8T4
} 7,$z;Lr0S
2&(sa0*y
?/#}ZZK^
public String getSSiteURL() _%@=Uc6V
{ %:C ]7gQ
return sSiteURL; FH5ql~
} .m4;^S2cO
[w\?j,
f|7u_f
public void setSSiteURL(String value) :VA.QrKW
{ ~%y@Xsot>
sSiteURL = value; -M5=r>1;
} >H|` y@]
e(B9liXM
ug&[ IL~lc
public String getSFilePath() sKaE-sbJY
{ b3$k9dmxV+
return sFilePath; T3&`<%,f
} /\d$/~BFi
UHO_Z
]gb=
public void setSFilePath(String value) S[:xqzyDg
{ irBDGT~
sFilePath = value; g^>#^rLU
} v Y|!
V_^@
~[PKcEX
public String getSFileName() m>&HuHf
{ ~4,I7c7
return sFileName; ><?BqRm+
} `m~syKz4A
V`hu,Y;%
e_3CSx8Cc
public void setSFileName(String value) ?:rx1}:F
{ h rN%
sFileName = value; o@E/r.uK
} -7-['fX
Kf,-4)
TW&DFKK`
public int getNSplitter() dWRrG-'
{ ``Q2P%
return nSplitter; ^C^*,V3
} D@YP7
Yn51U6_S
&%aXR A#+
public void setNSplitter(int nCount) =(r* 5vd
{ $6f\uuTU2"
nSplitter = nCount; D$k8^Vs
} ,\PVC@xJ
} +*nGp5=^GE
@!tVr3;N$
9L eNe}9v
/* #TJk-1XM*q
**Utility.java m@xi0t
*/ oUDVy_k
package NetFox; |VH!)vD
!|wzf+V
eOlKbJU
public class Utility { h\[\\m O
AD5) .}[F
WPuz]Ty
public Utility() M++0zhS
{ ,%"xH4d
_uxPx21g}
mPZGA\
} 3C>qh{z"
JHV)ZOO
//线程睡眠 &M&{yc*%
public static void sleep(int nSecond) CX/(o]
{ D}mL7d1
try{ &wH:aD
Thread.sleep(nSecond); QOFvsJ<s
} H:&?ha,9
catch(Exception e) >O`l8tM
{ 0Dv JZ|e
e.printStackTrace (); !-]C;9Zd
} ~XM[>M\qB
} 8}p8r|d!ls
<EX7WA
//日志 |(IO=V4P
public static void log(String sMsg) 0OZMlt%z
{ [2Mbk~
System.err.println(sMsg); 1hQN8!:<
} oW}!vf3z
T`YwJ6N
]TpU"JD
public static void log(int sMsg) U\<-mXv
{ T3J'fjY
System.err.println(sMsg); ks(SjEF
} @|-OJ4[5
} a=}*mF[ug
[IX+M#mf
|WqOk~)[Z3
/* `$;+g ,
**TestMethod.java 6DF
*/ `x8Bn"
package NetFox; <>&=n+i
BR_TykP
D#rrW?-z
public class TestMethod { C*~aSl7
h BMH)aU
eQN.sl5
public TestMethod() JNU/`JN9f
{ ///xx/weblogic60b2_win.exe I2Ev~!
try{ TRvZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #*$p-I=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dDcZ!rRaL@
SiteFileFetch fileFetch = new SiteFileFetch(bean); =yiOJyx
fileFetch.start(); 7qIB7_K5
} '&yg{n
catch(Exception e){e.printStackTrace ();} Q\_{d0 0
[[L-jq.'
:R6Q=g=
} F4I6P
#;r]/)>
S q@H
public static void main(String[] args) w<nv!e?
{ kyUl{Zj
new TestMethod(); ISqfU]>[
} $ @1u+w
} $~u.Wq
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