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)); 7LZb*+>
} ].T;x|
for(int i=0;i<nEndPos.length-1;i++) 5!Mp#lO
{ C`T5d
nEndPos = nStartPos[i+1]; Ac(irPrD
} f<Um2YGW
nEndPos[nEndPos.length-1] = nFileLength; |iJZC
} 9n\#s~,
} -/7=\kao%
h+u|MdOY\
=v`&iL~m
//启动子线程 y^|3]G3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j%y+W{Q[
for(int i=0;i<nStartPos.length;i++) hA1hE?c`
{ &OR*r7*Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w[vIPlSdS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x4A~MuGU
nStartPos,nEndPos,i); wQS w&G
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $ 5-2cL
fileSplitterFetch.start(); @`*YZq>p
} L , Fso./y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M~Dc5\T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); f#Oz("d
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %=O!K>^vt<
nEndPos = " + nFileLength); 4^}PnU7z
// fileSplitterFetch[nPos.length-1].start(); }`FC__
{Qmb!`F
uqeWdj*Y
//等待子线程结束 N6 (w<b
//int count = 0; k)' z<EL6c
//是否结束while循环 CIvT5^}
boolean breakWhile = false; 7Bd_/A($
'R5l =Wf
nln[V$
while(!bStop) HZ4 ^T7G
{ I[IQFka}
write_nPos(); OiEaVPSI;
Utility.sleep(500); `rJ ~*7-
breakWhile = true; J` --O(8Ml
M@[gT?mv1
]@T `qR
for(int i=0;i<nStartPos.length;i++) X1qj l_A
{ Guc^gq}
if(!fileSplitterFetch.bDownOver) cDyC&}:f
{ J|8YB3K,
breakWhile = false; N!&VBx^z
break; zvC,([
} "A`'~]/hE
} `;2`H, G'
if(breakWhile) Xn'>k[}<k
break; 19`0)pzZ*P
JN-8\L
U*h)nc
//count++; \eN/fTPm
//if(count>4) ew['9
// siteStop(); 1vudT&
} <$6E r
FdHWF|D
_u5U> w
System.err.println("文件下载结束！"); +N&(lj
} w.-i !Ls
catch(Exception e){e.printStackTrace ();} %4K#<b"W
} %d\+(:uu/
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wf$ JuHPt
//获得文件长度 (W/UR9x)|d
public long getFileSize() e2ZUl` {g
{ L KR,CPz
int nFileLength = -1; ,R6$SrNcd
try{ ZWEzL$VWi
URL url = new URL(siteInfoBean.getSSiteURL()); F4gc_>{|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !qve1H4d2
httpConnection.setRequestProperty("User-Agent","NetFox"); t4f\0`jN
YWF<2l.
v]S8!wU
int responseCode=httpConnection.getResponseCode(); bZfJG^3
if(responseCode>=400) %,RU)}
{ lB@K;E@r8
processErrorCode(responseCode); =R`2m
return -2; //-2 represent access is error !PbFo%)
} ?V&a |:N9
nEr, jd~f
K6hNN$F!
String sHeader; +q%goG8
PyE<`E
dBn.DU*B
for(int i=1;;i++) `d#_66TLr
{ +=$G6uR$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j'n= Xh
//Utility.log(in.readLine()); j`lK}
sHeader=httpConnection.getHeaderFieldKey(i); _zwuK1e
if(sHeader!=null) M/;g|J jM
{ ^Tmmx_Xw
if(sHeader.equals("Content-Length")) 6nhB1Aei
{ t/(j8w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); FM];+d0
break; b=EZtk6>
} 9Ua@-
} /% 1lJD
else ]h@:Y]
break; OSU=O
} Q)&Ztw<
} mj~CCokF{?
catch(IOException e){e.printStackTrace ();} Y [S^&pF
catch(Exception e){e.printStackTrace ();} *%sYajmD
P*]g*&*Y +
;oE4,
Utility.log(nFileLength); Lq^/Z4L
VTa8.(i6v
f#mpd]e+6
return nFileLength; -XB>&dNl)T
} zZQoY_UI
dGjvSK<1@
K2Zy6lGOZ
//保存下载信息（文件指针位置） I*"]!z1
private void write_nPos() ;'}xD5]
{ _Qas+8NW
try{ Jsl,r+'H
output = new DataOutputStream(new FileOutputStream(tmpFile)); R)z|("%ec
output.writeInt(nStartPos.length); v>R.ou(
for(int i=0;i<nStartPos.length;i++) =c'LG
{ A:Z:&(NtE:
// output.writeLong(nPos); K.~U%v}
output.writeLong(fileSplitterFetch.nStartPos); #$E vybETx
output.writeLong(fileSplitterFetch.nEndPos); ,5:86'p
} +0DIN4Y(4
output.close(); C54)eT6
} _u; UU$~
catch(IOException e){e.printStackTrace ();} HL]?CWtGP
catch(Exception e){e.printStackTrace ();} xm5D$m3#
} P2kZi=0
huIr*)r&p
lvlH5Fc
//读取保存的下载信息（文件指针位置） %iv'/B8
private void read_nPos() wd*Jq
{ E3qX$|.$/
try{ $? Rod;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); q[lqEc
int nCount = input.readInt(); pV8,b
nStartPos = new long[nCount]; -_(!
nEndPos = new long[nCount]; zO,sq%vQn'
for(int i=0;i<nStartPos.length;i++) /^"TMm
{ .wywO|
nStartPos = input.readLong(); >xN^#$ng}
nEndPos = input.readLong(); gUcE,L
} CgWj9 [
input.close(); Pcc%VQN
} A 3l1$t#w
catch(IOException e){e.printStackTrace ();} )NK2uD
catch(Exception e){e.printStackTrace ();} RWE%?`
} M}>q>
JQqDUd
frt?*|:
private void processErrorCode(int nErrorCode) {T9g\F*
{ ZpyRvDz
System.err.println("Error Code : " + nErrorCode); tznT*EQr
} jWz-7BO
1N&U{#4
U&NOf;h$
//停止文件下载 nJnan,`W
public void siteStop() 7>'F=}6[Y
{ g=.5*'Xlp
bStop = true; *HRRv.iQ
for(int i=0;i<nStartPos.length;i++) lMP7o&
fileSplitterFetch.splitterStop(); F-6* BUqJ
?#'qY6 ^
WBGYk);
} k)J7) L
} k1<Py$9"
//负责部分文件的抓取 {SJLM0=Z
**FileSplitterFetch.java c?d#Bj ?
*/ TJ<PT
package NetFox; E$T#o{pai
/D q]=P
>Pu*MD;
import java.io.*; (bw;zNW
import java.net.*; P|?z1JUd
R[(,wY_1
H_Yy.yi
public class FileSplitterFetch extends Thread { =cQwR:):
ATU@5,9
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String sURL; //File URL [qz6_WOo
long nStartPos; //File Snippet Start Position aj\'qRrU$
long nEndPos; //File Snippet End Position `C1LR,J
int nThreadID; //Thread's ID R8E<;^?j
boolean bDownOver = false; //Downing is over L%DL n
boolean bStop = false; //Stop identical i0P+,U
FileAccessI fileAccessI = null; //File Access interface "YBA$ef$
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r{btBv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V6L_aee}CK
{ M$)+Uo2
this.sURL = sURL; >dM'UpN@
this.nStartPos = nStart; Wwz>tE
this.nEndPos = nEnd; PIA&s6U
nThreadID = id; 3B0%:Jj
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;# {x_>M
} (7IF5g\
LCG<
_YY)-H
public void run() }LRAe3N%8
{ I4*N
while(nStartPos < nEndPos && !bStop) kB 2bT}
{ sw&Qks?V
v6GWD}HH,
Zj JD@,j
try{ %F7aFvl*
URL url = new URL(sURL); ^ey\ c1K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m} V,+E
httpConnection.setRequestProperty("User-Agent","NetFox"); IH0Uq_
String sProperty = "bytes="+nStartPos+"-"; 0C7"*H0R
httpConnection.setRequestProperty("RANGE",sProperty); bhI8b/
Utility.log(sProperty); x\=h^r#w
myo/}58Nv
)-9/5Z0v
InputStream input = httpConnection.getInputStream(); [kXe)dMX8
//logResponseHead(httpConnection); =FE,G*
$$4% .J26Z
4@5<B
byte[] b = new byte[1024]; X>CYKRtb
int nRead; DFiexOb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (X8N?tJ
{ L]VK9qB
nStartPos += fileAccessI.write(b,0,nRead); }N[sydL
//if(nThreadID == 1) 7+c@pEU]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kSDV#8uZ
} Z` Aiw."|
(*EN!-/
K,RIa0)
Utility.log("Thread " + nThreadID + " is over!"); D,7! /u'
bDownOver = true; #8`G&S*
//nPos = fileAccessI.write (b,0,nRead); R'F|z{8
} V;z?m)ur
catch(Exception e){e.printStackTrace ();} ka5>9E
} X[|>r@Aa!
} V6!oe^a7'
7}*5Mir p
1/gh\9h
//打印回应的头信息 UeRenp
public void logResponseHead(HttpURLConnection con) s"'1|^od
{ q q`UvU
for(int i=1;;i++) 8'YL!moG|
{ /#XO!%=7
String header=con.getHeaderFieldKey(i); X2{3I\'Ft
if(header!=null) Q=dR[t>^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l`1ZS8 [.
Utility.log(header+" : "+con.getHeaderField(header)); \h yTcFb
else koUH>J:
break; E>ev/6ox
} g5cR.]oz
} |h'ugx1iY
6`yq4!&v
!=-l760
public void splitterStop() bNC1[GG[
{ 9Hu%Z/[!p
bStop = true; 0+L5k!1D
} C>;}CH|X
iU3co|q7
NO<myN+N
} DQ~@=%?ni
.v;Npm2
.-r 1.'.A
/* }vL[N~5\
**FileAccess.java =gj]R
*//文件访问(定位，写) )FB)ZK;
package NetFox; 4Qw!YI#40$
import java.io.*; Jn&(v"_
|k^X!C0
Wbc %G8
public class FileAccessI implements Serializable{ ZF`ckWT:-N
-AbA6_j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6q5V*sJ&
RandomAccessFile oSavedFile; AXJC&O}`
long nPos; \UiuJ+
H: U_k68
"XH]B
public FileAccessI() throws IOException TEYbB=.
{ gC'GZi^
this("",0); 2n@"|\uHD
} o~~_>V)W
5?Bi+fg
fpzTv3D=I
public FileAccessI(String sName,long nPos) throws IOException L'c4i[~s
{ & z?y
oSavedFile = new RandomAccessFile(sName,"rw"); u-?&~WA
this.nPos = nPos; a E#s#Kv
oSavedFile.seek(nPos); Lrk^<:8;
} f5O*Njl
l@^RbF['
U$-FQRM4K
public synchronized int write(byte[] b,int nStart,int nLen) jW6@U%[!b
{ wOOPuCw?
int n = -1; tkd2AMkh!
try{ dCc*<S
oSavedFile.write(b,nStart,nLen); :&Ul
n = nLen; I*0W\Qz@
} Hv%a\WNS1
catch(IOException e) & MAIm56~
{ iA:CPBv_mu
e.printStackTrace (); b)df V=
} c xX
DO0["O74
|S.-5CAh4
return n; Y H?>2u
} pE=wP/#
8*|@A6ig
2Ay2 G-
} q k!Q2W
Q@M,:0+cy
`a<G7
/* 9m#`56G`
**SiteInfoBean.java yJr'\(
*/ SX;FBO(p
package NetFox; wK,tq
h5Z%|J>;0
y<5s)OehG
public class SiteInfoBean { ]A_)&`"Cb
z`/v}'d[X
lfCoL@$6D
private String sSiteURL; //Site's URL ;KnnAZJ
private String sFilePath; //Saved File's Path <8H`y(S
private String sFileName; //Saved File's Name [jafPi(#g
private int nSplitter; //Count of Splited Downloading File c|I{U[(U
xOS4J+'s@
LEk W^Mv
public SiteInfoBean() ^*Ca+22xO
{//nSplitter的缺省值为5 af> i
//default value of nSplitter is 5 b|4h2iuM
this("","","",5); H1q>UU:
} AN^;~m^
K}Aaflq
(=7e~'DC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ZZ4W?);;
{ m+1MoeR
sSiteURL= sURL; ^d!-IL_
sFilePath = sPath; fa$ Fo(.
sFileName = sName; {At1]>
this.nSplitter = nSpiltter; ]2v31'
W~gFY#w
sYeZ.MacU
} vZ|m3;X
Bm^vKzp
{y :/9
public String getSSiteURL() 7|H !(a'
{ 2&P'rmFm
return sSiteURL; fLPB *y6
} 3:S Ex;d+
V}3.K\7
=7Nm=5@
public void setSSiteURL(String value) P hn&hRAO
{ +8v!vuO'
sSiteURL = value; j_Dx4*vg
} (2<0kqj%
,u!c|4
J#bEAK^L,l
public String getSFilePath() i9+V<'h
{ YMJ?t"
return sFilePath; I2D<~xP~2+
} '|Cs!Zl
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?e yo2:-$
public void setSFilePath(String value) ij%\ld9kd
{ MB:E/
sFilePath = value; M]eH JZ~v
} Rh,*tS
MX qH
:fo%)_Jc!
public String getSFileName() +xB!T1pD
{ 3_ObCsJ#,
return sFileName; lO)p
} t[7YMk
O[Nc$dc
wB"&K;t
public void setSFileName(String value) 4km=KOx[
{ c7S<ex,
sFileName = value; f |aO9w
} / [:@j+n\
7@MVInV9
oO!@s`
public int getNSplitter() YP+0uZ[g
{ vlx wt~
return nSplitter; OY/QA
} ss |<\DE+
omY%sQ{)
^uC1\!Q1
public void setNSplitter(int nCount) n omtP }
{ _qM'm^z5
nSplitter = nCount; JYs*1<
} NC|&7qQ
} |$^,e%bE
1u'x|Un
M'Q{2%:>a
/* QV7K~qi
**Utility.java RCnN+b:c
*/ ,RDxu7iT
package NetFox; E~jNUTq
=^O84Cp 6
3]M YHb
public class Utility { SO3WOR`3
M"ZP s
AZxOq !B
public Utility() {PWz:\oaD
{ *~4w%U4T0
'BcxKqC
F[ m^(x
} i8+kc_8#d
u3w `(3{<
//线程睡眠 :/K 'P`JaL
public static void sleep(int nSecond) Ds$FO}KD{
{ }|&M@Up
try{ Y?R;Y:u3Z
Thread.sleep(nSecond); p;U[cGHC
} ycIT=AFYqd
catch(Exception e) @| qnD
{ `N;u#z
e.printStackTrace (); L*11hyyk
} {>pB
} O=G2bdY{,
v5RS<?o
//日志 _LxV)
public static void log(String sMsg) Yk6fr~b
{ 's(0>i
System.err.println(sMsg); WOzdYeeG
} SG$/v
kT[]^Jtc
LPvyfD;Zy
public static void log(int sMsg) u,*$n'l]
{ \/. Of]YQ
System.err.println(sMsg); 4cTJ$" v
} 0`3ey*
} &W)ks
Z#3wMK~
fZ 17
/* yAi#Y3!::
**TestMethod.java p$0;~1vH
*/ 6WzE'0Nyr
package NetFox; VgN`' iC`I
!c\s)&U7B
&:nWZ!D
public class TestMethod { mAX]m1s
)U`H7\*)
kS[k*bN0
public TestMethod() pzCD' !*
{ ///xx/weblogic60b2_win.exe uZW ?0W
try{ U]@t\T3W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4Q,HhqV'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -~p@o1k0
SiteFileFetch fileFetch = new SiteFileFetch(bean); (TDLT^
fileFetch.start(); NV^ktln
} (IAl$IP63s
catch(Exception e){e.printStackTrace ();} k'xnl"q
<xOpm8
8L|rj4z<#
} 7'xT)~*$4
7"Zr:|$U
e*jn7aya
public static void main(String[] args) ]9]3=;b>
{ ghx8dX}
new TestMethod(); lva]jh2
} ,D [
} BB1'B-O
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