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)); i,G )kt'H
} hGc')
for(int i=0;i<nEndPos.length-1;i++) {. r/tV5IH
{ rw*#ta O
nEndPos = nStartPos[i+1]; ;dq AmBG{8
} &^-quzlZ
nEndPos[nEndPos.length-1] = nFileLength; K>H_q@-?f
} X2#;1 ku
} Oh9jr"Gm=
:hB 8hTw]p
v&:R{
//启动子线程 ,~@0IKIA Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lqC a%V
for(int i=0;i<nStartPos.length;i++) i2<dn)K[~-
{ z`b.~<P
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @C),-TM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 41swG
nStartPos,nEndPos,i); J('p'SlI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r{m"E^K,
fileSplitterFetch.start(); 8e_ITqV%
} wg?:jK
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V+A1O k)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "Q*Z?6[Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hM*T{|y
nEndPos = " + nFileLength); L@rKG~{Xy
// fileSplitterFetch[nPos.length-1].start(); #vN\]e
)9@I7QG?
gd9ZlHo'Id
//等待子线程结束 pH&Q]u;O
//int count = 0; kTQ`$V(>&
//是否结束while循环 'ad|@Bh
boolean breakWhile = false; Jt4T)c9
c9e }P
h#bpog
while(!bStop) 1a{~B#
{ "yMr\jt~-
write_nPos(); =U3,P%
Utility.sleep(500); %v++AcE
breakWhile = true; xBGSj[1`i
fT.5@RR7^
9.5hQZ
for(int i=0;i<nStartPos.length;i++) Hl&]r'bK
{ >iP>v`J
if(!fileSplitterFetch.bDownOver) cm]D"GFLY
{ ;FYiXK%
breakWhile = false; _\ n'uW$
break; k07JMS?
} bA#E8dlC_
} 1{+Ni{
if(breakWhile) [.P~-6~
break; &libC>a[
3"'|Ql.H
]3#_BL)M8p
//count++; U[~BW[[@f
//if(count>4) ~..h=
// siteStop(); c4CBpi?}
} 1N<)lZl)
~AuvB4xe~
k}-%NkQ 9O
System.err.println("文件下载结束！"); D@H'8C\
} Y=/3_[G
catch(Exception e){e.printStackTrace ();} FK!9to>
} NXDV3MH=
R{.wAH(
Ki-CJy
//获得文件长度 57+^T}/>
public long getFileSize() ?,|_<'$4T
{ $Vp&Vc8
int nFileLength = -1; r2QC$V:0
try{ <u44YvLBm
URL url = new URL(siteInfoBean.getSSiteURL()); $i@5'[jA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?|^1-5l3
httpConnection.setRequestProperty("User-Agent","NetFox"); *n?6x!A
;3'}(_n
'dj}- Rs
int responseCode=httpConnection.getResponseCode(); J.":oD
if(responseCode>=400) Z.m.Uyz{7
{ HkxFDU-K
processErrorCode(responseCode); I_xJ[ALdm
return -2; //-2 represent access is error y)U8\
} ,=>O/!s
`(.ue8T
cZL"e
String sHeader; _}Jz_RS2`
f7OfN#I
fx.FHhVu
for(int i=1;;i++) UeE& 8{=d
{ l)VMF44
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5n.4>yOY
//Utility.log(in.readLine()); c#9 zw[y-L
sHeader=httpConnection.getHeaderFieldKey(i); ^f!d8 V
if(sHeader!=null) &nPv%P,e
{ !0`ZK-nA6
if(sHeader.equals("Content-Length")) 4$.UVW\
{ ) !ZA.sx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -$WiB
break; {b/60xl?
} $if(`8
} ~"EkX
else wb4 4
break; _a*Wk
} hUGIy(
} ~2A<fL,-
catch(IOException e){e.printStackTrace ();} }SpMHR`
catch(Exception e){e.printStackTrace ();} iO#H_&L.p
"_'9KBd!
!l6B_[!@
Utility.log(nFileLength); 9L:v$4{LU
;?inf`t
f{ S)wE>;
return nFileLength; 1t!Mg{&e[x
} 2T?t[;-
Jc9SHCJ
\"Sqr(~_
//保存下载信息（文件指针位置） ? dSrY
private void write_nPos() 2%vwC]A
{ ,O a)
try{ oF V9t{~j
output = new DataOutputStream(new FileOutputStream(tmpFile)); /q='~t
output.writeInt(nStartPos.length); .:RoD?px
for(int i=0;i<nStartPos.length;i++) [Z Ea3/
{ |hp_X>Uv'
// output.writeLong(nPos); 0e vxRcrzz
output.writeLong(fileSplitterFetch.nStartPos); ?WUE+(oH>
output.writeLong(fileSplitterFetch.nEndPos); pJ_Z[}d)c
} FG#E?G
output.close(); 5+%BZ
} P'ZWAxd
catch(IOException e){e.printStackTrace ();} aKCCFHq t!
catch(Exception e){e.printStackTrace ();} WlZ[9,:p1
} Q1eiU Y6
y L&n)
[zf9UUc~
//读取保存的下载信息（文件指针位置） f.+e
private void read_nPos() FIU(2
{ |BYD]vK
try{ {2Gp+&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {AIZ,
int nCount = input.readInt(); ~sSB.g
nStartPos = new long[nCount]; -ZihEyG?V
nEndPos = new long[nCount]; :sT<<LtI-
for(int i=0;i<nStartPos.length;i++) z eIBB
{ UQW;!8J#R(
nStartPos = input.readLong(); >y]YF3?
nEndPos = input.readLong(); :X`J1E]Rjd
} &2?kD{
input.close(); zP=J5qOZ8
} bk4%lYJ"
catch(IOException e){e.printStackTrace ();} $8it&/JP,
catch(Exception e){e.printStackTrace ();} ]s,T` (&
} OgHWmb
d\Dxmb]o
6oUT+^z#
private void processErrorCode(int nErrorCode) ol`]6"Sc
{ ^Gs!"Y
System.err.println("Error Code : " + nErrorCode); _5y)m5I
} PrN?;Z.
iQa Q"s
2? !b!
//停止文件下载 kFk+TXLDIt
public void siteStop() O~aS&g/sf
{ RNvtgZ}k{X
bStop = true; de ](l687I
for(int i=0;i<nStartPos.length;i++) pd X9G
fileSplitterFetch.splitterStop(); OZt'ovY
t]vX9vv+D
I/^Lr_\
} ?'_iqg3
} m?B@VDZ
//负责部分文件的抓取 ?+Qbr$]
**FileSplitterFetch.java (x=NA )
*/ K{|;'N-1
package NetFox; Q_uv.\*z_
o~GhV4vq
C!Tl?>Tt
import java.io.*; s_1]&0<
import java.net.*; ^uZ%d
o)-Qd3d%S
hZzsZQ`
public class FileSplitterFetch extends Thread { .2Rh_ful
\-sDRW
$~ItT1k_
String sURL; //File URL !4z"a@$
long nStartPos; //File Snippet Start Position Jge;/f!i
long nEndPos; //File Snippet End Position 4L5Wa~5\
int nThreadID; //Thread's ID 6'wP?=
boolean bDownOver = false; //Downing is over m&ZdtB|
boolean bStop = false; //Stop identical C8G['aQ
FileAccessI fileAccessI = null; //File Access interface =~HX/]zF
$rjv4e}7
@[JQCQ#r
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D%50
{ LQ{4r1,u]
this.sURL = sURL; {ZfTUt)-P
this.nStartPos = nStart; <w,aS;v6jp
this.nEndPos = nEnd; c8}1-MKs_R
nThreadID = id; vk#xCggK
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @ObsW!g
} p(x[zn+%Y
'x6Mqv1W
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public void run() 1^$Io}o:S
{ e94csTh=
while(nStartPos < nEndPos && !bStop) fk",YtS*
{ 7`WK1_rR\
;2X1qw>
xSLN
try{ &2) mpY8xQ
URL url = new URL(sURL); .eeM&n;c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 74Kl!A
httpConnection.setRequestProperty("User-Agent","NetFox"); j4NS5
String sProperty = "bytes="+nStartPos+"-"; PqP)<d'/
httpConnection.setRequestProperty("RANGE",sProperty); myJsRb5
Utility.log(sProperty); 7qh_URt@
%l5J
Y8CXinh
InputStream input = httpConnection.getInputStream(); 2oq>tnYyV[
//logResponseHead(httpConnection); {(aJrSE<z
%OzxR9
8"S0E(,mu
byte[] b = new byte[1024]; Ajq<=y`NzV
int nRead; )I5f`r=Ry
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a{)"KAP
{ 9h9Y:i*Gh5
nStartPos += fileAccessI.write(b,0,nRead); #~ >0Dr
//if(nThreadID == 1) Y*7.3 +#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Kk/qd)nk
} `#l_`j=r$
WRo#ZVt9$
fd)}I23Q'
Utility.log("Thread " + nThreadID + " is over!"); l5@k8tnz
bDownOver = true; (2a~gQGD
//nPos = fileAccessI.write (b,0,nRead); ~w!<J-z)
} X#Hs{J~@p
catch(Exception e){e.printStackTrace ();} kszYbz"
} Li7/pUq>}!
} ixU1v~T
-aec1+o
46$5f?Z
//打印回应的头信息 `Y'}\>.#
public void logResponseHead(HttpURLConnection con) @s@r5uR9B
{ UDxfS4yI
for(int i=1;;i++) Pu}2%P)p
{ `[`eg<xj
String header=con.getHeaderFieldKey(i); Wk$%0xZ7
if(header!=null) jI y'mGaG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q4Cw{2r
Utility.log(header+" : "+con.getHeaderField(header)); `VS/Xyp
else "\e9Y<
break; TT29LC@
} %3~jg
} _\u'~wWl
X}S<MA`
6rR}qV,+{
public void splitterStop() "S6d^
{ 1 "4AS_Q
bStop = true; [Si`pPvl
} <ZCjQkka>r
xe_c`%_
%)]{*#N4
} [dUW3}APV
3ne=7Mj
)kg^.tP
/* 5)mn
**FileAccess.java )2:d8J\
*//文件访问(定位，写) 5 kQC
package NetFox; 1vQ*Br
import java.io.*; ZfIQ Fh>
g9 g &]
`@eQL[Z9x
public class FileAccessI implements Serializable{ [x9eamJ,H
V<(cW'zA/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M`S >Q2{
RandomAccessFile oSavedFile; NO;+:0n
long nPos; B6|=kl2C
bY]aADv\
*n}{)Ef
public FileAccessI() throws IOException >a]{q^0
{ X&(1DE
this("",0); %m{h1UQQ+
} WG1x:,-
!WAbO(l
lKwIlp
public FileAccessI(String sName,long nPos) throws IOException 3M/kfy
{ ])vM# f
oSavedFile = new RandomAccessFile(sName,"rw"); z,$^|'pP
this.nPos = nPos; Dy0RZF4_
oSavedFile.seek(nPos); i?||R|>;"'
} joYj`K
dTS7l02
CSIW|R@
public synchronized int write(byte[] b,int nStart,int nLen) JrS|Ib)6
{ 4fQ<A <2/
int n = -1; $Z$BF
try{ Br;1kQ%eC
oSavedFile.write(b,nStart,nLen); EtKy?]i
n = nLen; M/>^_zG
} KN_3]-+B
catch(IOException e) MT}9T
{ a$"3T
e.printStackTrace (); s}X2*o`,
} 05$CIS>!
>'7Icx
8,=,'gFO
return n; <D!"<&N
} !-p5j3A4L
arET2(h
r ",..{
} eUQrn>`
x7>' 1
`Z0FQ( r_
/* K#tT \
**SiteInfoBean.java z'j4^Xz?%$
*/ Qne@Vf kA
package NetFox; bRfac/:}
?7*.S Lt
Qw}uB$S>
public class SiteInfoBean { Y'mtMLfMc
(gQP_Oa(
Rcc9Tx(zvQ
private String sSiteURL; //Site's URL xo a1='
private String sFilePath; //Saved File's Path l|j
private String sFileName; //Saved File's Name /R!:ll2
private int nSplitter; //Count of Splited Downloading File O,x[6P54P
C[6} 8J|
`zwXfY,%
public SiteInfoBean() ))66_bech
{//nSplitter的缺省值为5 QVJq%P
//default value of nSplitter is 5 ,` 6O{Z~
this("","","",5); 2Jo|]>nl}u
} lK 5@qG#
Qzt'ZK
s'b 4Me
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y 3h`uLQ
{ FC@h6\+a
sSiteURL= sURL; ?(0=+o(`
sFilePath = sPath; qILb>#
sFileName = sName; k{d]
this.nSplitter = nSpiltter; N:x--,2
~G,_4}#"pM
_wH>h$E
} VkdGGY
1-0tG+
/W9(}Id6
public String getSSiteURL() ' Dcj\=8
{ >mJH@,F:
return sSiteURL; y)vK=,"
} /#jH#f[
)0+6^[Tqq
0Q?)?8_
public void setSSiteURL(String value) FkE)~g
{ KW-GVe%8f
sSiteURL = value; /oOZ>B%1s
} E@,m+
N,W ?}
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public String getSFilePath() z36wWdRa6
{ d^MRu#]
return sFilePath; 'b)qP|
} _NefzZWUJ
:aQ.:b(n
mC2K &'[
public void setSFilePath(String value) ~(nc<M[
{ =' uePM")
sFilePath = value; 7-:R{&3Lm:
} .V4-
(Zg'])
0vX4v)-^u
public String getSFileName() xt_:R~/[
{ aD]! eP/)
return sFileName; 0FSNIPx
} "i#aII+T
Jvc:)I1NE7
bTU[E
public void setSFileName(String value) vAp<Muj(a
{ <qg4Rz\c]
sFileName = value; n,U?]mr
} ZDg(D"
KpA1Ac)T
?4A/?Z]ub
public int getNSplitter() &AN1xcx\
{ B (Ps/
return nSplitter; H2H`7 +I,
} *Nm$b+
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I4W@t4bZ
public void setNSplitter(int nCount) $=iw<B r
{ _%q~K (::
nSplitter = nCount; jp_|pC'
} =Ox}WrU~
} #x;,RPw5
/>Q}0Hg
aaP_^m O
/* NV7k@7_{B
**Utility.java q3AqU?f
*/ s1q8r!2\w
package NetFox; c/Xg ARCO
rtS' 90`
7:,f|>
public class Utility { s$).Z(6
=:aJZ[UU<2
w lH\w?
public Utility() AHRJ7l;a
{ ak7kb75o
8l_M 0F,
')U~a
} 2]1u0-M5L
U.KQjBi
//线程睡眠 V(_1q
public static void sleep(int nSecond) B*N1)J\5
{ y(o)}m*0
try{ J91[w?,
Thread.sleep(nSecond); ,Cb3R|L8
} B2e"
catch(Exception e) /TyGZ@S>m
{ gs5(~YiT6
e.printStackTrace (); ]I[~0PCSX
} @(Y!$><Is
} 6$6QAW0+f
8q@Z
//日志 pZ&,YX
public static void log(String sMsg) <%HRs>4
{ 4b:|>Z-
System.err.println(sMsg); PVsKI<
} 7p{Pmq[
7 !$[XD
0V4B Q:v
public static void log(int sMsg) n:,mo}?X
{ &^r>Q`u
System.err.println(sMsg); OvtE)ul@
} z Fo11;*D
} f<NR6],}
f#=c=e-A
G 5;6q
/* ?@ F2Kv
**TestMethod.java x;17}KV
*/ q0iJy@?A
package NetFox; maXg(Lu
_dJ(h6%3
5J10S
public class TestMethod { Nob(D'vSr
y3zP`^
Ix5&B6L8
public TestMethod() rW:krx9
{ ///xx/weblogic60b2_win.exe );$99t
try{ TaN{xpo
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); rZ~w_DK*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); flsejj$
SiteFileFetch fileFetch = new SiteFileFetch(bean); )h8}{*
fileFetch.start(); bC/":+s& p
} KwuucY
catch(Exception e){e.printStackTrace ();} Upe}9xf
{_QdB;VwH
1u 9hA~rj
} p+CUYo(
iRzFA!wH
<s9?9^!!V^
public static void main(String[] args) =V[uXm
{ ~SnUnNDm`
new TestMethod(); Jsz!ro
} Z!)~?<gcq:
} n t}7|h|
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