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)); 7ksh%eV
} .] mYpz
for(int i=0;i<nEndPos.length-1;i++) 9qN4f8R
{ oJa6)+b(3
nEndPos = nStartPos[i+1]; YL-/z4g
} U/F<r3.`#
nEndPos[nEndPos.length-1] = nFileLength; _OV\W'RrA
} @)PA9P |
} 6(awO2{BP
**_`AM~
D,q=?~
//启动子线程 g?`g+:nug
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t\~lGG-p
for(int i=0;i<nStartPos.length;i++) i)9}+M5
{ ;,P-2\V/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QR4rQu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &7z79#1NS
nStartPos,nEndPos,i); U<,@u,_Ja
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2gz}]_
fileSplitterFetch.start(); ]@X5'r"
} z@;]Hy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e~R; 2bk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .{sKEVK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *z[G+JX
nEndPos = " + nFileLength); ^?PU:eS
// fileSplitterFetch[nPos.length-1].start(); 88}+.-3t$
>dKK [E/[d
'f&o%5]
//等待子线程结束 $$ %4,\{l
//int count = 0; y_O[r1MF
//是否结束while循环 n,sf$9"
boolean breakWhile = false; "hwg";Z$n
f!6oW(r-L
Y.` {]rC
while(!bStop) Y<|!)JLB2
{ 0\v98g<[+
write_nPos(); )006\W|t9
Utility.sleep(500); W}m-5L
breakWhile = true; ! |SPOk
qu]ch&"?U
b`"E(S/
for(int i=0;i<nStartPos.length;i++) I)#=#eI*:
{ iEx.BQ+
if(!fileSplitterFetch.bDownOver) <@i.~EL
{ v{{Cj83S+
breakWhile = false; L%](C
break; u8ofgcFYE
} ^0"^Xk*
} Ow7NOhw
if(breakWhile) RC7|@a
break; +|}R^x`z
:g)0-gN
g8^\|
//count++; W>C!V
//if(count>4) h(}$-'g
// siteStop(); dWHl<BUm
} v|5:;,I
`nBCCz'Y!
nQ|4.e;
System.err.println("文件下载结束！"); zNSix!F
} iVq4&X_x
catch(Exception e){e.printStackTrace ();} @L^Fz$Sx
} .d< +-w2Mu
m-f"EFmP
fR_ jYP1
//获得文件长度 GwiG..Y]&
public long getFileSize() HI/]s^aL
{ 1I({2@C
int nFileLength = -1; G| 7\[!R
try{ 89@\AjI
URL url = new URL(siteInfoBean.getSSiteURL()); 8N<0|u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W{E22J}
httpConnection.setRequestProperty("User-Agent","NetFox"); H /Idc,*
IV{,'+hT
JFaxxW
int responseCode=httpConnection.getResponseCode(); [NcS[*qp
if(responseCode>=400) ;t!n%SnK9!
{ ,h21 h?6
processErrorCode(responseCode); e&[gde(
return -2; //-2 represent access is error qW]gp7jK4
} >)ZX
Enee\!@v
~;St,Fw<<
String sHeader; +EJwWDJ!%
#PnuR2s7.
S,T?(lSl
for(int i=1;;i++) }.Eq_wP<
{ WqN=D5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \m-fLX
//Utility.log(in.readLine()); %M8Egr2|0
sHeader=httpConnection.getHeaderFieldKey(i); a%*l]S0z"
if(sHeader!=null) R'a%_sACj>
{ wu?ahNb.`Y
if(sHeader.equals("Content-Length")) AH`n
{ i^P@?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ZJ(/cD
break; 97:1L4w.(
} * d6[kY
} wUzQ`h2
else "%~\kJ(G
break; PoMkFG6
} ps0wN%tA
} Q,Tet&in )
catch(IOException e){e.printStackTrace ();} ]2G5ng' @
catch(Exception e){e.printStackTrace ();} 6cof Zc$
>}QRMn|@H
{#q']YDe`
Utility.log(nFileLength); y e!Bfz>
'B}pIx6k~
tf64<j6
return nFileLength; D|I(2%aC
} RAR0LKGX
7t-j2 n`<
4X7y}F.J
//保存下载信息（文件指针位置） Wz$%o'OnC
private void write_nPos() %VYQz)yW
{ G)gf +)W
try{ <B6@q4Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); CCKg,v
output.writeInt(nStartPos.length); WtI1h`Fo
for(int i=0;i<nStartPos.length;i++) H3{x;{.b
{ :QgC Zq
// output.writeLong(nPos); Mq) n=M
output.writeLong(fileSplitterFetch.nStartPos); E#"QaI8`
output.writeLong(fileSplitterFetch.nEndPos); \C.%S +u
} 1A^iUC5)
output.close(); A9PXu\%y
} q0WW^jwQ
catch(IOException e){e.printStackTrace ();} PJj{5,#@3
catch(Exception e){e.printStackTrace ();} =/=x"q+X
} 2{s ND
J<DV7zV
b~06-dk1
//读取保存的下载信息（文件指针位置） j`Lf/S!}
private void read_nPos() iHjo3_g)n
{ +C7 1".i-
try{ 7=XQgbY/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); l|`FW
int nCount = input.readInt(); }yqRz6=YB
nStartPos = new long[nCount]; J#*Uf>5NY
nEndPos = new long[nCount]; `7jm
for(int i=0;i<nStartPos.length;i++) Fk D
{ mOwgk7s[J
nStartPos = input.readLong(); :NU-C!eT
nEndPos = input.readLong(); s#w+^Mw$
} N>`+{
input.close(); "M6a_rZ2W
} #1Mk9sxo
catch(IOException e){e.printStackTrace ();} EZ #UdK_
catch(Exception e){e.printStackTrace ();} *lv)9L+0
} @RotJl/>
etf ft8
La%\-o
private void processErrorCode(int nErrorCode) 7UHqiA`L
{ ?97MW a
System.err.println("Error Code : " + nErrorCode); Z_' %'&Y
} q?z6|]M|u
*pP"u::S
0kgK~\^,.O
//停止文件下载 cb&y8!ci~
public void siteStop() t )Z2"_5
{ 5X&<+{bX
bStop = true; Bir}X
for(int i=0;i<nStartPos.length;i++) R+]p -NI^
fileSplitterFetch.splitterStop(); %9M; MK
r0G#BPgdR
d_J?i]AP|'
} DjOFfD\MF
} "b%hAdR
//负责部分文件的抓取 2a.NWJS
**FileSplitterFetch.java wlqV1.K
*/ u#p1W|\4
package NetFox; EC1q#;:
,2JqX>On>Y
GQqw(2Ub}
import java.io.*; *p?b"{_a
import java.net.*; q`1t*<sk
{#QFDA
2`5(XpYe
public class FileSplitterFetch extends Thread { sxL;o>{
]wne2WXE
d1e'!y}R5
String sURL; //File URL &o"Hb=k<
long nStartPos; //File Snippet Start Position 5K'EuI)
long nEndPos; //File Snippet End Position 7i{Rn K6*
int nThreadID; //Thread's ID @usQ*k
boolean bDownOver = false; //Downing is over +azPpGZ=
boolean bStop = false; //Stop identical PB>p"[ap4
FileAccessI fileAccessI = null; //File Access interface ~b\7qx_a9
JoW*)3Z
_zh}%#6L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UShn)3F
{ '5ky<
this.sURL = sURL; XyS#6D
this.nStartPos = nStart; Y@eHp-[
this.nEndPos = nEnd; H[@}ri<
nThreadID = id; R'dF<&Kj|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &4*&L.hPM^
} CcY.8|HT
%>I!mD"X\
!P@u4FCs
public void run() yfTnj:Fz
{ n_Um)GI>
while(nStartPos < nEndPos && !bStop) u;J=g
{ EfDo%H^!j
?;)(O2p
vCH>Fj"7
try{ q,nj|9z V
URL url = new URL(sURL); "]c:V4S#`A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6./&l9{h+
httpConnection.setRequestProperty("User-Agent","NetFox"); EVO5+
String sProperty = "bytes="+nStartPos+"-"; FGwz5@|E
httpConnection.setRequestProperty("RANGE",sProperty); DP^{T/G
Utility.log(sProperty); )\mklM9Z
5mSXf"R^
wT*N{).
InputStream input = httpConnection.getInputStream(); mf}?z21vD
//logResponseHead(httpConnection); 3tXtt@Yy
O.rk!&N
v@>hjie
byte[] b = new byte[1024]; P]Gsc
int nRead; oeIB1DaI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) XQj`KUO@
{ 9q* sR1
nStartPos += fileAccessI.write(b,0,nRead); Br#]FB|tD
//if(nThreadID == 1) w-/bLg[L?$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s #L1:L
} :\80*[=;Z
#S<>+,Lk
}GkEv}~t
Utility.log("Thread " + nThreadID + " is over!"); nWXI*%m5
bDownOver = true; BOwkC;Q[
//nPos = fileAccessI.write (b,0,nRead); ~Ag!wj
} ,?&hqM\
catch(Exception e){e.printStackTrace ();} (3]7[h7
} WDzov9ot
} 7%7_i%6wP
tm]75*?
fiw~"2U
//打印回应的头信息 B|extWwu
public void logResponseHead(HttpURLConnection con) z[t$[Qg
{ ybS7uo
for(int i=1;;i++) J|xqfY@+
{ a*SJHBB
String header=con.getHeaderFieldKey(i); {+C>^b
if(header!=null) QJ"Bd`wc
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vpXS!o>/Sn
Utility.log(header+" : "+con.getHeaderField(header)); 6bb=;
else 5j]}/Aq
break; {xM%3
} ~]"}s(J;
} k(^zhET
HwU \[f
$wN'mY
public void splitterStop() :eIBK
{ !5A nr
bStop = true; v0$6@K;M4G
} 9MHb<~F
ny=CtU!z
(Mtc&+n{
} GuDus2#+
+,|-4U@dl
Rb9Z{Clq>
/* d9Q%GG0]
**FileAccess.java 3[V|C=u0
*//文件访问(定位，写) 5lU`o
package NetFox; 9l,Gd
import java.io.*; @L0wd>
HvTi^Fb\a
^2mXXAQf7^
public class FileAccessI implements Serializable{ N}dJ)<(2~
Kjf#uU.7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3i s.c)
RandomAccessFile oSavedFile; ?L'k2J
long nPos; U3za}3
g` h>:5]
x65e,'
public FileAccessI() throws IOException @{nT4{
{ ,$}Q#q
this("",0); hG ]jm
} Pu9.Uwx
F8=6!Qj
Jp= (Q]ab
public FileAccessI(String sName,long nPos) throws IOException Wc]Fg9E
{ hqBwA1](a
oSavedFile = new RandomAccessFile(sName,"rw"); BryMq !
this.nPos = nPos; ntF(K/~Y
oSavedFile.seek(nPos); SjJUhTb
} FcWu#}.p}
xv%}xeEV
F;_;lRAb
public synchronized int write(byte[] b,int nStart,int nLen) QU#/(N(U#T
{ kh5V&%>?
int n = -1; 3$kZu
try{ XG[%oL
oSavedFile.write(b,nStart,nLen); PAc~p8S
n = nLen; Kp&d9e{ Yc
} bZlAK)
catch(IOException e) V2y[IeSQ
{ ;{ezK8FJ}@
e.printStackTrace (); $`5DGy?RU
} q OXL(
zCQv:.0L
r;'!qwr
return n; "*T)L<G
} \UC4ai2MK
O^<6`ku
~kHir]jc
} "ulaF+
m&%N4Q~X>
2MC\~"L<
/* "E8!{
**SiteInfoBean.java ydFY<Mb(o
*/ 'Oc8[8
package NetFox; NMDNls&)k
4v!@9.!vQ
%z2nas$$g
public class SiteInfoBean { 1dq.UW\
yO($KL+
K4rr.f6
private String sSiteURL; //Site's URL d-*9tit
private String sFilePath; //Saved File's Path V4"AFArI
private String sFileName; //Saved File's Name z=xHk|+'
private int nSplitter; //Count of Splited Downloading File 3}+/\:q*
h1Lp:@:|
5FzRusNiA
public SiteInfoBean() Cse0!7_T
{//nSplitter的缺省值为5 c`>\R<Z ]
//default value of nSplitter is 5 dOhV`8l
this("","","",5); wiVQMgi`
} W@G[ gS\T
_c&*'IY[V
T'V(%\w
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )_=&)a1U
{ Z:*U/_G
sSiteURL= sURL; A`r9"([-A
sFilePath = sPath; kgIWgk%
sFileName = sName; ^DH*@M
this.nSplitter = nSpiltter; vBpg6 fX
~;+vF-]R
MJb = +L
} wx!*fy4hL
V;6M[ic}
~L1O\V i
public String getSSiteURL() Z^|C~lp;n
{ bXfOZFzq)
return sSiteURL; `8-aHPF-
} 6?lg 6a/eO
rNAu@B
J'EK5=H
public void setSSiteURL(String value) M;9+L&p=
{ =6dKC_Q
sSiteURL = value; 0 mQ3P.9
} HB}gn2.1&
$7r wara
`SW " RLS3
public String getSFilePath() KCFwO'
{ mx[^LaR>v
return sFilePath; o`U\Nhq
} VB#31T#q?
? 1{S_
@Otc$hj
public void setSFilePath(String value) KCu6:)6'
{ ^ZlV1G;/W@
sFilePath = value; -7$'* V9$
} {q)B@#p
JXAyF6 $
YUb,5Y0
public String getSFileName() L,Nr,QC-
{ >(rB[ZJ
return sFileName; ^;3rdBprm
} CJOl|"UyJ
]aRD6F:L
S=g-&lK
public void setSFileName(String value) v6VhXV6$|
{ i6CYD
sFileName = value; Ak1)
} ]mj+*l5
55DzBV
Vr1|%*0Tv
public int getNSplitter() >l1Yhxd_0*
{ IpJv\zH7
return nSplitter; O)|4>J*B
} Ltw7b
<`3(i\-X
@qDrTH]5
public void setNSplitter(int nCount) @,&m`qzd+
{ @>@Nug2
nSplitter = nCount; QL2y,?Mz7
} B|=maz:_
} aTm.10{^
weV#%6=5\
pCUOeQL(
/* zrO|L|F&P
**Utility.java ss{=::#
*/ uq%3;#[0
package NetFox; Nj_sU0Dt
C<t>m_t9
m#$za7
public class Utility { }?J5!X
RM1uYFs<
CD1=2
public Utility() _0["J:s9
{ /A.i5=k
/&:9VMMj
j2 ^T:q[
} l&Ghs@>Kl
dO;vcgvb
//线程睡眠 xg^^@o
public static void sleep(int nSecond) @%nUfG7TQ
{ xJLO\B+gM
try{ TY\"@(Q|G
Thread.sleep(nSecond); 25n(&NV
} 'F?Znd2L
catch(Exception e) !s*''v*
{ 0r ; nz]'
e.printStackTrace (); Ww&- `.
} VQ<i$ I
} TDE1z>h+"
X&?lDL7?
//日志 _1> 4Q%
public static void log(String sMsg) {U '&9_y
{ ENWB|@B
System.err.println(sMsg); wV&f|JO0+
} doO Ap9%
<lmJa#
y6Epi|8
public static void log(int sMsg) {dx /p-Tv
{ 0o$HC86w
System.err.println(sMsg); wv.Ulrpx.
} s]vJUC,s
} 6a?$=y
`ab\i`g9
([CnYv
/* x<j"DS}S)D
**TestMethod.java ?U/Wio$@
*/ |id79qY7g
package NetFox; XQJ^)d00h
u%1k
8C,utjy
public class TestMethod { if[o?6U4t
4_762Gu%
@Du}
public TestMethod() Y`7#[g
{ ///xx/weblogic60b2_win.exe #!Cter2
try{ #G+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -Bo~"q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hRa(<ZK
SiteFileFetch fileFetch = new SiteFileFetch(bean); Eh@T W%9*
fileFetch.start(); + lB+|yJ+
} Mev-M2A
catch(Exception e){e.printStackTrace ();} zt[4_;2Y
+:]Aqyc\
EPe]-C`
} NVc!g
-)OkG#J@
B.mbKntK)R
public static void main(String[] args) aDl, K;GL
{ *Qg5Z
new TestMethod(); ZE8/ m")
} &[ u6oAR
} X`3vSCn
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