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)); Urm&4&y
} i'H{cN6
for(int i=0;i<nEndPos.length-1;i++) =XzrmPu
{ mHM38T9C%
nEndPos = nStartPos[i+1]; I ^?TabL
} <ZSH1~<{6
nEndPos[nEndPos.length-1] = nFileLength; *l)_&p
} $.a<b^.Xi
} Mi%i_T^i
ylUxK{
:"5i/Cx
//启动子线程 -=H*(M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }rj.N98
for(int i=0;i<nStartPos.length;i++) -+Axa[,5=
{ lG I1LUo
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YiJnh47
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !TA6-]1
nStartPos,nEndPos,i); EcxPbRg
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yS^";$2Tc
fileSplitterFetch.start(); GbUw:I
} Iojyku\W.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (dd+wx't
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~Z9Eb|B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \T`InBbf
nEndPos = " + nFileLength); _PLY<i2vr
// fileSplitterFetch[nPos.length-1].start(); |`+kZ-M*
B7zyMh
= NHuj.
//等待子线程结束 ##+|zka!U
//int count = 0; ]-QY, k
//是否结束while循环 s6bILz-u
boolean breakWhile = false; 3=5K7F
d[E~}Dq3#
YT'G#U1x~
while(!bStop) jd8`D6|Z
{ dn(I$K8
write_nPos(); Aslh}'$}-
Utility.sleep(500); -sO[,
breakWhile = true; Rah"La
d3-F?i 5d
]L+YnZ?6
for(int i=0;i<nStartPos.length;i++) yY_(o]k
{ ~QgyhJM_h=
if(!fileSplitterFetch.bDownOver) +Ysm6n '
{ !~Vo'ykwx'
breakWhile = false; 2;Vss<hR4A
break; 5.m&93P
} hgIqr^N9
} 1P4cBw%
if(breakWhile) BIGln`;,f
break; ~puXZCatN
URU,&gy=
,;;7+|`
//count++; HYcLXhvgu
//if(count>4) e_RLKFv7
// siteStop(); 8T6LD
} s?Lx\?T
s%M#
X$*MxMNs
System.err.println("文件下载结束！"); O2i7w1t
} zs/4tNXw
catch(Exception e){e.printStackTrace ();} ot\ FZ
} SeuC7!q{
[|iWLPO1&k
<PLQY
//获得文件长度 C,;T/9
public long getFileSize() YcQ$nZAU
{ r<'ni
int nFileLength = -1; {!RDb'Zp
try{ >+,w2m@0
URL url = new URL(siteInfoBean.getSSiteURL()); ')R+Z/hG.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E_q/*}]pE
httpConnection.setRequestProperty("User-Agent","NetFox"); G5WQTMzf&
HQp\0NC]
q+iG:B/Z
int responseCode=httpConnection.getResponseCode(); pbCj ^
if(responseCode>=400) :1*q}R
{ DWv(|gO
processErrorCode(responseCode); ^bM\:z"M
return -2; //-2 represent access is error e p jb
} J`6IH#54
[^Z)f<l
R*[X. H
String sHeader; #|PPkg%v<
@h&:xA56
Ky0}phGRu
for(int i=1;;i++) ^fiJxU
{ _0cCTQE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7xF)\um
//Utility.log(in.readLine()); r'J="^k{
sHeader=httpConnection.getHeaderFieldKey(i); r` B(ucE
if(sHeader!=null) agV z
{ &Fiesi!tET
if(sHeader.equals("Content-Length")) M)F_$ ICE-
{ zqHG2:MN"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); HLe/|x\@<
break; zG0]!A
} m?<^b_a}
} Sj ly]
else t[e]AU[}
break; ]'NL-8x">
} eo@kn yA<&
} PglSQ2P
catch(IOException e){e.printStackTrace ();} jn 5v
catch(Exception e){e.printStackTrace ();} (*M*muk
HNRAtRvnY
/[=Yv!
Utility.log(nFileLength); S$O5jX 0
"MvSF1
_/czH<
return nFileLength; kwXUjnp
} 0 <E2^
ZEp>~dn;
XU`ly3!
//保存下载信息（文件指针位置） v<Ywfb
private void write_nPos() >akC
{ ]xkh"j+W
try{ "38L ,PW0Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); dWx@<(`OC
output.writeInt(nStartPos.length); J-|&[-Z
for(int i=0;i<nStartPos.length;i++) ih|;H:"^
{ =]r2;014
// output.writeLong(nPos); A<] $[2qPj
output.writeLong(fileSplitterFetch.nStartPos); bv;.6C(T<
output.writeLong(fileSplitterFetch.nEndPos); 1V wcJd
} hx*4xF
output.close(); YQ@2p?4m
} G|*&owJ
catch(IOException e){e.printStackTrace ();} !F:mDZeY
catch(Exception e){e.printStackTrace ();} :?}mu1
} EJP]E)
\11+~
%Z+**>1J
//读取保存的下载信息（文件指针位置） Kx?.g#>U;
private void read_nPos() v}J0j
{ !PA><F
try{ I94-#*~I
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $|g ;
int nCount = input.readInt(); OkAgO3>Y/
nStartPos = new long[nCount]; Z4X, D`s
nEndPos = new long[nCount]; #K`0b$
for(int i=0;i<nStartPos.length;i++) #sg*GK+|:R
{ q9H\ $
nStartPos = input.readLong(); E]v]fy"
nEndPos = input.readLong(); ubZJUm
} lX-i<0`
input.close(); U{KnjoS
} )"?eug}D
catch(IOException e){e.printStackTrace ();} |VzXcV-"8)
catch(Exception e){e.printStackTrace ();} jU kxA7 }}
} 0VrsbkS
d/T&J=
\4LTViY]
private void processErrorCode(int nErrorCode) 6uv~.-T<l
{ J>k 6`gw
System.err.println("Error Code : " + nErrorCode); ZqdoYU'
} /\_n5XI1
0WfnX>(C7R
1hlU 6=Y
//停止文件下载 9=j)g
public void siteStop() AAs&P+;
{ [Y$TVwFwX
bStop = true; `|Hk+V
for(int i=0;i<nStartPos.length;i++) >_xuXEslUz
fileSplitterFetch.splitterStop(); g1?9ge1
liG|#ny{
g~b$WV%
} 5~/EAK`
} -)B_o#2=2
//负责部分文件的抓取 DRR)mQBb
**FileSplitterFetch.java \@yJbhk
*/ FF#+d~$z
package NetFox; q*4U2_^.
AC'_#nPL#
a$h^<D ^
import java.io.*; v-SXPL]_^
import java.net.*; Ll-QhcC$
JBLUX,
'e' p`*
public class FileSplitterFetch extends Thread { utBrH
W;cYg.W2
a;^lOU|L{
String sURL; //File URL {l5fKVb\C
long nStartPos; //File Snippet Start Position HzKY2F(,
long nEndPos; //File Snippet End Position Y)]C.V,~
int nThreadID; //Thread's ID z6l'v~\
boolean bDownOver = false; //Downing is over x~R,rb
boolean bStop = false; //Stop identical `Fo/RZOW
FileAccessI fileAccessI = null; //File Access interface \>pm (gF
0IdA!.|
L'S,=NYXY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "OK[uug
{ $,]U~7S
this.sURL = sURL; T@i* F M
this.nStartPos = nStart; ZAU#^bEQB
this.nEndPos = nEnd; qbeUc5`1
nThreadID = id; YI;iG[T,&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $-Ex g*i
} CYQ)'v
~CkOiWC0
fglfnx0{
public void run() ![_0GFbT
{ v\4<6Z:4
while(nStartPos < nEndPos && !bStop) Wh| T3&
{ ;s{'cN[.
~gff{Nzk
b^C27s
try{ =t)qy5
URL url = new URL(sURL); <7F-WR/2n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z:7eroZP
httpConnection.setRequestProperty("User-Agent","NetFox"); p> >H$t
String sProperty = "bytes="+nStartPos+"-"; 0V>HoH
httpConnection.setRequestProperty("RANGE",sProperty); 1u7D:h>#
Utility.log(sProperty); 2;WbXc!#!
.4[3r[
} v:YSG
InputStream input = httpConnection.getInputStream(); 1J/'R37lP
//logResponseHead(httpConnection); !pw)sO~
ed#fDMXGQ%
MkoK(m{7
byte[] b = new byte[1024]; HrvyI)4{
int nRead; [UZr|F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) f%@~|:G:
{ r4X}U|s!0
nStartPos += fileAccessI.write(b,0,nRead); o4WQA"VxM
//if(nThreadID == 1) reh{jMC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q0VAkVHw4
} r5S/lp+Y+N
JOY&YA$U
hFv{?v
Utility.log("Thread " + nThreadID + " is over!"); Z>g>OPu
bDownOver = true; Ge-Bk)6
//nPos = fileAccessI.write (b,0,nRead); )wM%Ul<s
} O;<wDh)Yt
catch(Exception e){e.printStackTrace ();} 3;BIwb_
} * &:_Vgu
} `hj,rF+4
}^Q:Q\
%5gdLm!p
//打印回应的头信息 bp:`m>4<
public void logResponseHead(HttpURLConnection con) F5 ]<=i
{ z eT`kZ
for(int i=1;;i++) lEFd^@t
{ Mi8)r_l%O
String header=con.getHeaderFieldKey(i); f_S$CFa@
if(header!=null) bKCE;Wu:G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -[-oz0`Sl{
Utility.log(header+" : "+con.getHeaderField(header)); `w:kY9
else H u;"TG
break; 1 6zxPSTr}
} -|m3=#
} !\7`I}:
B~KxUp
V'XEz;Ze
public void splitterStop() O0qG 6a
{ bzNnEH`^]
bStop = true; R}0gIp=
} dRJ ](Gw
H<_Tn$<zH.
4<#ItQ(
} ;pW8a?
)_jboaNzwI
KNAvLcg
/* rc8HZ
**FileAccess.java ~{Iw[,MJ
*//文件访问(定位，写) -iDs:J4Iq
package NetFox; (WT\HR
import java.io.*; +x 3x
]XEyG7D
1YV1Xnn,
public class FileAccessI implements Serializable{ 6LDZ|K@
JU>~[yAP
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :b44LXKCP
RandomAccessFile oSavedFile; 71nZi`AR
long nPos; m0bxVV^DK!
Mgw#4LU
1$T`j2s
public FileAccessI() throws IOException .z,-ThTH@\
{ yQrgOdo,w
this("",0); %"H:z
} /+92DV
,"`20.Lv
*U1*/Q.
public FileAccessI(String sName,long nPos) throws IOException o!BCR:
{ b/UXO$_~-
oSavedFile = new RandomAccessFile(sName,"rw"); R@3HlGuRKw
this.nPos = nPos; @o0HDS
oSavedFile.seek(nPos); \7LL neq
} ([q>.[WbH]
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)jL@GW
public synchronized int write(byte[] b,int nStart,int nLen) nN{DO:_o
{ bW W!,-|R
int n = -1; g&g:HH:
try{ QgU]3`z"
oSavedFile.write(b,nStart,nLen); |^8ND#x
n = nLen; _K9PA[m5~
} ^N<aHFF
catch(IOException e) GhfhR^P
{ Ja3#W K
e.printStackTrace (); i`@cVYsL
} oqwW
MlWKfe<
jF;<9-m&
return n; \*CXXp`
} ??nT[bhQ
w]MI3_|'r(
2tK~]0x
} n/;{-
-btNwE6[.
BPkMw'a:
/* jW#dUKS(
**SiteInfoBean.java ;0WAfu}#H
*/ |h $Gs2
package NetFox; =&pR=vl
%t_'rv
LeN }Q
public class SiteInfoBean { E~q3o*
~*EipxhstJ
1R-0b{w[
private String sSiteURL; //Site's URL eW.qMx#:od
private String sFilePath; //Saved File's Path ;L87 %P(.
private String sFileName; //Saved File's Name 60~*$`
private int nSplitter; //Count of Splited Downloading File MkVv5C
}%wP^6G*x\
7Z]?a
public SiteInfoBean() Z=-#{{bv
{//nSplitter的缺省值为5 9hK8dJw
//default value of nSplitter is 5 d3EN0e+^
this("","","",5); Onqapm0
} gm]q<~eMW
@B{
+q2\3REzx
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o$bQ-_B`
{ mKM[[l&A
sSiteURL= sURL; 2O(k@M5E?
sFilePath = sPath; br0\O
sFileName = sName; f(}&8~&
this.nSplitter = nSpiltter; d+P<ce2G
T:Q+ Z }v+
0F!Uai1
} sfG9R"
:zC=JvKT
X%!?\3S
public String getSSiteURL() !K_<7iExI\
{ :;#^gvH
return sSiteURL; #\F8(lZ
} d?U,}tv
:'t"kS
8oHIXnK
public void setSSiteURL(String value) %xx;C{g;a
{ Qmd2C&Xw
sSiteURL = value; ~Gg19x.#uW
} " d~M\Az
KPK`C0mg@k
V!e`P
public String getSFilePath() bMqS:+
{ M(^IRI-
return sFilePath; D_f:D^
} y#ON=8l
50S*_4R
T/L\|_:'
public void setSFilePath(String value) /KiaLS
{ ojWf]$^y}
sFilePath = value; N:^4OnVR
} 1{xkAy0
A[88IMZs
-RThd"
public String getSFileName() sQzr+]+#9
{ mh_GYzd
return sFileName; '~6l 6wi
} DqH]FS?]
|Pse=_i
Fw#wVs)@:
public void setSFileName(String value) n u>6UjV
{ +zFEx%3^
sFileName = value; KC\W6|NtGj
} y3 S T"U
(n{!~'3
1rmN)
public int getNSplitter() zy9W{{:P(1
{ >F!X'#Iv
return nSplitter; na/,1iI<
} XOY\NMo
PurY_
QRY7ck:N
public void setNSplitter(int nCount) 6;\Tps;A
{ Of$gs-
nSplitter = nCount; fVBu?<=d
} %t-}dC&
} QTI^?@+N>
%aJ8wYj*
]O68~+6
/* qB=%8$J
**Utility.java }l@7t&T|
*/ ]FO)U
package NetFox; fPsUIlI/A
E'_$?wWn5
^$\#aTyFK
public class Utility { yi1V\8DC
oO,"B8a
\E:l E/y
public Utility() BO=j*.YKy
{ u!VY6y7p
F|W(_llfM
wo!;Bxo N
} h|&qWv
q"^T}d d,
//线程睡眠 qgLj^{
public static void sleep(int nSecond) [U?a %$G>
{ 5},kXXN{+
try{ ,n+~S^r
Thread.sleep(nSecond); +QVe -
} |h1Y3
catch(Exception e) 2JRX ;s~
{ wrt^0n'r)c
e.printStackTrace (); XB-l[4?
} }>u<,
} 9l9|w4YJs
5l(Q#pSX
//日志 *6%r2l'kZ
public static void log(String sMsg) CpF&Vy K
{ rY&Y58./
System.err.println(sMsg); e!~x-P5M`
} /WKp\r(Hp
%]i("21
/SZg34%
public static void log(int sMsg) -( ,iwFb
{ q+-Bl
System.err.println(sMsg); gcfEJN4'
} m2$Qp{C6H
} V|8`]QW@
BWN[>H %S
,d34v*U
/* l6EDl0~r
**TestMethod.java v(tr:[V
*/ p#95Q
package NetFox; \hwz;V.J"
C7[CfcPA
m^)h/s0A
public class TestMethod { o!+jPwEU
MzsDDP+h
qrmJJSJ
public TestMethod() ?0VLx,kp
{ ///xx/weblogic60b2_win.exe M(2c{TT
try{ a~F`{(Q2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); n3kYVAgF
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iE$/ Rcp
SiteFileFetch fileFetch = new SiteFileFetch(bean); !Z6GID})p
fileFetch.start(); >@BvyZ)i
} L@{5:#-
catch(Exception e){e.printStackTrace ();} &<P!o_+eb
>Cjb|f3'i}
G*|2qX"o
} 3wBc`vJ!
Y`u.P(7#
<eq93
public static void main(String[] args) =y/VrF.bV
{ r$*p
new TestMethod(); <,Zk9 t&
} dB`YvKr#
} j/R
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