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)); XPnHi@x
} !!cN4X
for(int i=0;i<nEndPos.length-1;i++) [h8macx
{ vY,D02EMw
nEndPos = nStartPos[i+1]; \]dvwN3x
} Z.s0ddMs
nEndPos[nEndPos.length-1] = nFileLength; (CJx Y(1K
} A5_r(Z-5
} Ue"pNjd|
YgjN*8w\
.S4%Q9l
//启动子线程 GLMpWD`Wo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Dz8aJ6g
for(int i=0;i<nStartPos.length;i++) tX,x%(
{ fX>y^s?y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ToD_9i }6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D.ySnYzh
nStartPos,nEndPos,i); _N0N#L4M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /a6i`
fileSplitterFetch.start(); 2@I0p\a
} J6<O|ng::
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /Ba/gq0j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); QUh`kt(E
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .8;0O M
nEndPos = " + nFileLength); "^Y zHq6
// fileSplitterFetch[nPos.length-1].start(); P'*Fd3B#A=
kdhwnO
Vjd>j; H
//等待子线程结束 rZ2cC#
//int count = 0; P?zaut
//是否结束while循环 x@[6u
boolean breakWhile = false; e0<O6
$I4Wl:(~}
U"~W3vwJ
while(!bStop) KleiX7
{ 5Yww,s
write_nPos(); oY7jj=z#T
Utility.sleep(500); tk>J mcTw
breakWhile = true; M|{NC`fa
0s RcA-9
jdx T662q
for(int i=0;i<nStartPos.length;i++) ~=|QPO(d
{ J93xxj
if(!fileSplitterFetch.bDownOver) t6lwKK
{ #&%>kfeJ)<
breakWhile = false; i?7?I
break; "b%FkD
} kv;P2:"|
} 77ztDQDtM
if(breakWhile) Ds#BfP7a
break; |IS$Om
F07X9s44E
p./0N.
//count++; aK7}}
//if(count>4) !%.=35NS@E
// siteStop(); i6g=fx6j*
} v-/vj/4>
$dA]GWW5A
15r=d
System.err.println("文件下载结束！"); {w7/M]m-
} ExeZj8U
catch(Exception e){e.printStackTrace ();} E=`/}2
} c5:X$k\
Z[eWey_
2(m#WK7>F
//获得文件长度 sz%_9;`dpL
public long getFileSize() mkl^2V13~
{ 1I)oT-~
int nFileLength = -1; C2\zbC[qm
try{ A~ _2"
URL url = new URL(siteInfoBean.getSSiteURL()); *N"CV={No
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n=|% H'U
httpConnection.setRequestProperty("User-Agent","NetFox"); C7DwA/$D
.8T0OQ4
]'-y-kqY
int responseCode=httpConnection.getResponseCode(); n7yp6Db
if(responseCode>=400) -:OJX#j
{ FZLx.3k4
processErrorCode(responseCode); c] t@3m
return -2; //-2 represent access is error h_SkX@"/-
} II!~"-WH
=G"ney2
K9y~ e
String sHeader; TPak,h(1
ww #kc!'
VqxK5
for(int i=1;;i++) \ Ce*5h
{ e`OQ6|.k8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1:>F{g
//Utility.log(in.readLine()); Ez-Q'v(9
sHeader=httpConnection.getHeaderFieldKey(i); _l"nwEs
if(sHeader!=null) lk[Y6yE
{ L"n)fe$
if(sHeader.equals("Content-Length")) >[;=c0(
{ h9#)Eo
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); n.z,-H17
break; PB?2{Cj
} c&FOt
} 0U H]
else RZ;s_16GQ
break; Poa&htxe1
} py+\e"s
} 32j}ep.*
catch(IOException e){e.printStackTrace ();} Dad$_%
catch(Exception e){e.printStackTrace ();} z|X6\8f
cD}]4
H-U_
Utility.log(nFileLength); V)N{Fr)&
q=V'pML
k)|.<
return nFileLength; RtzSe$O
} >%0$AW|Exu
_B&Lyg!J
Z6A-i@
//保存下载信息（文件指针位置） nSC2wTH!1
private void write_nPos() @NqwJ.%g
{ q!?*M?Oz
try{ Y)+q[MZ R
output = new DataOutputStream(new FileOutputStream(tmpFile)); O#^H.B
output.writeInt(nStartPos.length); \7"|'fz
for(int i=0;i<nStartPos.length;i++) I "~.p='
{ G3%Ju=
// output.writeLong(nPos); )1KyUQ\e
output.writeLong(fileSplitterFetch.nStartPos); l-l7jq]R
output.writeLong(fileSplitterFetch.nEndPos); V3cKbk7~
} x|(pmqIH+
output.close(); \ "$$c
} )<:TpMdUk
catch(IOException e){e.printStackTrace ();} .\glNH1d
catch(Exception e){e.printStackTrace ();} T9H*]LxK
} L/V^#$
});Rjg
7-!n-
//读取保存的下载信息（文件指针位置） DQm%=ON7
private void read_nPos() e)g&q'O
{ n=vDEX:'
try{ *{!Y_FrL
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fzQR0
int nCount = input.readInt(); $R1I(sJ
nStartPos = new long[nCount]; ,0q1Id
nEndPos = new long[nCount]; ]MosiMJF
for(int i=0;i<nStartPos.length;i++) h0@a"DqK
{ f$ xp74hw3
nStartPos = input.readLong(); d6YXITL)\>
nEndPos = input.readLong(); 2_+>a"8Y
} 6AGZ)gX
input.close(); hN &?x5aC>
} Bhd)# P
catch(IOException e){e.printStackTrace ();} JHt U"
catch(Exception e){e.printStackTrace ();} I}3F'}JV<
} %BP>,E/w
,_I rE
I/MY4?(T
private void processErrorCode(int nErrorCode) bYnq,JRA
{ $2?AJ/2r$b
System.err.println("Error Code : " + nErrorCode); 0!_?\)X
} #e|o"R;/`
2 HEU
dD=$$( je
//停止文件下载 a3tcLd|7J
public void siteStop() 49$<:{~
{ 7upko9d/
bStop = true; ]HuB%G|t1V
for(int i=0;i<nStartPos.length;i++) _9 ]:0bDUo
fileSplitterFetch.splitterStop(); Y \-W`
~\jP+[>M'
V0>X2&.A
} >8>!wi9U
} ,=P&{38\q
//负责部分文件的抓取 =GPXuo
**FileSplitterFetch.java 3k`Q]O=OU
*/ |Ev|A9J!
package NetFox; d8wVhZKI"
&aLTy&8Fv
D}98ZKi
import java.io.*; 30!DraW8
import java.net.*; (WyNO QO'
e~N&?^M
-AdDPWn
public class FileSplitterFetch extends Thread { /I=|;FGq
X8$Mzeq
o$sD9xx
String sURL; //File URL %o0b~R
long nStartPos; //File Snippet Start Position P0,]`w
long nEndPos; //File Snippet End Position IR6W'vA
int nThreadID; //Thread's ID @MES.g
boolean bDownOver = false; //Downing is over /\w4k
boolean bStop = false; //Stop identical f^uiZb
FileAccessI fileAccessI = null; //File Access interface 4]h/t&ppq
WiS3W;
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &q-&%~E@
{ AG@gOm
this.sURL = sURL; c>_ti+
this.nStartPos = nStart; Hd|[>4Z
this.nEndPos = nEnd; <l{oE?N
nThreadID = id; k&ci5MpN
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &zdS9e-fF
} ""0Y^M2I
Rql/@j`JX
ga5Q
public void run() 9\_AB.Z:
{ /?'~`4!(
while(nStartPos < nEndPos && !bStop) K ze?@*
{ fp' '+R[
}=[p>3Dd
_;j1g%
try{ WigtTAh4
URL url = new URL(sURL); _O`p(6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h0tiWHw
httpConnection.setRequestProperty("User-Agent","NetFox"); PR%)3
String sProperty = "bytes="+nStartPos+"-"; )@NFV*@I
httpConnection.setRequestProperty("RANGE",sProperty); i1vz{Tc
Utility.log(sProperty); d4S4 e
V*jl
)QE6X67i
InputStream input = httpConnection.getInputStream(); r&]XNq'P9
//logResponseHead(httpConnection); wk|+[Rl;L
GY%9V5GB
7g\v (P
byte[] b = new byte[1024]; o$*(N
int nRead; <fvu) f
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Nw*<e ]uD
{ W"c\/]aD
nStartPos += fileAccessI.write(b,0,nRead); ?+t;\
//if(nThreadID == 1) ys9:";X;}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >dl5^
} 4YfM.~ 6
,*|Q=
4$xVm,n|
Utility.log("Thread " + nThreadID + " is over!"); (U:-z=E#1
bDownOver = true; cRLw)"|
//nPos = fileAccessI.write (b,0,nRead); ,HZ%q]*:~
} |?T=4~b
catch(Exception e){e.printStackTrace ();} ihrf/b
} fDy*dp4z
} uy{O
46>rvy.r
zPaubqB
//打印回应的头信息 CvU$Fsb
public void logResponseHead(HttpURLConnection con) >+M[!;m}
{ 8^UF0>`'
for(int i=1;;i++) jY=y<R_oK
{ @_ %RQO_X
String header=con.getHeaderFieldKey(i); cMY}Y [2c
if(header!=null) [c,V=:Cq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;'S,JGpvT
Utility.log(header+" : "+con.getHeaderField(header)); 3FiK/8mu
else /vSGmW-*
break; `K{}
} 1>Sfv|ZP,
} )'+[,z ;s
2;v:Z^&
:uCwWv
public void splitterStop() EO!,rB7I
{ t2dsYU/
bStop = true; sX1DbEjj[o
} 9JA@m
w"' Pn`T
|T<aWZb^=
} :h(HKMSk1
Y#F.{i
;M~,S^U
/* Y_%:%J
**FileAccess.java xuXPVJdi
*//文件访问(定位，写) <XLae'R
package NetFox; d5'Q1"{
import java.io.*; ]o] VS
Lz 1.+:Ag
UR'[?
public class FileAccessI implements Serializable{ s<YN*~
Lf9hOMHx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ey=2zo^F
RandomAccessFile oSavedFile; apL$`{>US
long nPos; aO1^>hy
=Y2 Rht
4/(#masIL
public FileAccessI() throws IOException eo]nkyYDP
{ IWv(GQx
this("",0); g{N}]_%Uh
} [icD*N<Gc
p/Ul[7A4e
KU8,8:yY
public FileAccessI(String sName,long nPos) throws IOException 3yx[*'e$
{ ljbAfd
oSavedFile = new RandomAccessFile(sName,"rw"); 1V2]@VQF
this.nPos = nPos; |=q~X}DA
oSavedFile.seek(nPos); M(C">L]8
} HyzSHI
-Lq+FTezE
7i"b\{5
public synchronized int write(byte[] b,int nStart,int nLen) V(`]hH0;T
{ _#{*I(l
int n = -1; ~R|9|k
try{ Tt: (l/1
oSavedFile.write(b,nStart,nLen); 2;Z 0pPR&
n = nLen; 6{)pF
} _^_3>}y5op
catch(IOException e) og";mC
{ xT>9ZZcE
e.printStackTrace (); V|YQhd0kv
} 89M'klZ
Q/|.=:~FO
&{j!!LL
return n; ?M:>2wl
} eA& #33
F(VVb(\jd
fw&*;az
} lAnq2j|
V*n$$-5 1-
7T/BzXr,B
/* \c\~k0u
**SiteInfoBean.java iy~h|YK;
*/ 'w,gYW
package NetFox; !=YEhQ-
?|ZbQz(bL
Ck/44Wfej
public class SiteInfoBean { qm_l# u6
rO#w(]
jRg/N_2'2
private String sSiteURL; //Site's URL i|{psA
private String sFilePath; //Saved File's Path ZLzc\>QX
private String sFileName; //Saved File's Name sywuS
private int nSplitter; //Count of Splited Downloading File y`oj\
(utP@d^
s~OcL 5
public SiteInfoBean() ^iONC&r
{//nSplitter的缺省值为5 6/<Hx@r (
//default value of nSplitter is 5 e 6mZ;y5_
this("","","",5); r|l?2 eO~
} \ ITd\)F%N
ec;
LcGKYl(\K
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) I0x)d`
{ ,yC..aI
sSiteURL= sURL; K<^p~'f4P
sFilePath = sPath; g|Lbe4?
sFileName = sName; W.^zN'a
this.nSplitter = nSpiltter; #ZJ 1\Ov
:6Z2@9.}w
+6uf6&.@~
} )h@PRDI_
/xUF@%rT
Q\4tzb]
public String getSSiteURL() E3 % ~!ZC
{ brmSJ7
return sSiteURL; \a+Q5g
} Ue \A ,
g7! LX[
R3G\Gchd
public void setSSiteURL(String value) lo!pslqsn
{ 1 3]e< '
sSiteURL = value; lG-B) F
} ]$drBk86bh
@RPQ1da
X{x(p
public String getSFilePath() (kR NqfX
{ }<~(9_+
return sFilePath; (d#&m+ g]
} Y$>NsgQn6
"m{i`<,
$,K@xq5
public void setSFilePath(String value) 'dWUE-
{ 'ge$}L}4
sFilePath = value; ogIu\kiZ
} EPJ>@A>;D
CJk"yW[,|
MB;rxUbhe3
public String getSFileName() +c/!R|h=S
{ LBq2({="
return sFileName; p0W<K
} VHPqEaR
&Y^4>y%
j_5&w Znq
public void setSFileName(String value) r^6@Zwox]
{ Qw5-/p=t
sFileName = value; &OJ?Za@p@)
} Pl=)eq YY
FS5iUH+5
tf6-DmMH
public int getNSplitter() Tv1oy%dK
{ zgz!"knVx
return nSplitter; ~~|Iw=:
} bM"?^\a&Q
3|!3R'g/ >
c$,1j%[)
public void setNSplitter(int nCount) lusUmFm'*
{ t]0DT_iE
nSplitter = nCount; E} ]=<8V
} QuEX|h,F
} C9?mxa*z
EVLL,x.~:z
w0;4O)H$O
/* 7[P-;8)tq
**Utility.java N {{MMIq
*/ L4B/ g)K
package NetFox; Mi#i 3y(
lr4wz(q<9
7_PY%4T"
public class Utility { QxG^oxU}
|pS]zD
0?oL zw&
public Utility() p*5_+u
{ 1K#[Ef4
OqS!y( (
im9w|P5
} Eoixw8hz
f.$[?Fi
//线程睡眠 $b2~Wj*-nJ
public static void sleep(int nSecond) ]e),#_M
{ "p3<-06
try{ ECA<%'$?E
Thread.sleep(nSecond); cH*")oD
} }wRm ~
catch(Exception e) _BA; H+M
{ LI@BB:)[
e.printStackTrace (); #8M?y*<I
} :QP1!
} "`cN k26JZ
f8[O]MrO;
//日志 ;G}
public static void log(String sMsg) ,x1OQ jtY
{ @@^iN~uf
System.err.println(sMsg); _f";zd
} B<L7`xL
T0dD:sN
~n@rX=Y)]0
public static void log(int sMsg) a(6h`GHo
{ @*<0:Q|m
System.err.println(sMsg); D|Q7dIZm
} ms5?^kS2O
} 6\I^]\YO
$adZ|Q\
?e6>dNw
/* wdP(MkaV
**TestMethod.java E"VFBKB
*/ rxX4Cw]\"y
package NetFox; hsrf2Xw[
^?H|RAp
$m#^0%
public class TestMethod { dq.U#Rhrx
.B<Bqr@?8
]w>o=<?b
public TestMethod() ]i(/T$?~
{ ///xx/weblogic60b2_win.exe 4@{?4k-cq
try{ _b%)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;6``t+]q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jr0j0$BF
SiteFileFetch fileFetch = new SiteFileFetch(bean); d2Q*1Q@u
fileFetch.start(); 8cOft ;|qB
} @:Zk,
catch(Exception e){e.printStackTrace ();} P~{8L.w!>W
sw}O g`U
6Ot~Q
} {aUTTEu
S=-$:65
^D+^~>f
public static void main(String[] args) B%uY/Mwz$
{ k*)sz
new TestMethod(); YhV<.2^k
} T4wk$R L
} `K5*Fjx
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