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)); d H? ScXM=
} .Pe9_ZH$W
for(int i=0;i<nEndPos.length-1;i++) ZtK\HDdp
{ PY`L$e
nEndPos = nStartPos[i+1]; 1svi8wh
} 9xFO]Y"
nEndPos[nEndPos.length-1] = nFileLength; Pao%pA.<
} KVkMU?6
} wG1l+^p
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z x@$RS+]
//启动子线程 "7,FXTaer
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; im]g(#GnKh
for(int i=0;i<nStartPos.length;i++) PE"v*9k
{ Ya#h'+}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), paW@\1Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :=Kx/E:1
nStartPos,nEndPos,i); n((vY.NDV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $bvJTuw
fileSplitterFetch.start(); ,lt8O.h-l
} t9^A(Vh"-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uLQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cK@jmGj+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xyA-P& N
nEndPos = " + nFileLength); /6KIl
// fileSplitterFetch[nPos.length-1].start(); krB'9r<wa`
o31Nmy Ni
`y^sITr
//等待子线程结束 H={&3poBz
//int count = 0; ;apzAF
//是否结束while循环 ?kTWpXx"=
boolean breakWhile = false; $s\UL}Gc
;@3FF
e5?PkFV^a1
while(!bStop) a.@qGsIH
{ :7g=b%;
write_nPos(); T6#CK
Utility.sleep(500); WC,+Cn e
breakWhile = true; `.%JjsD<
!ABiy6d
eq[Et +
for(int i=0;i<nStartPos.length;i++) &QNY,Pj
{ O(z}H}Fv
if(!fileSplitterFetch.bDownOver) cXnKCzSxZq
{ -|S]oJy
breakWhile = false; G8Z4J7^
break; i3VW1~.8
} Km#pX1]>e
} *\uM.m0$
if(breakWhile) _[K"gu
break; DgHaOAdU
b'YE9E
b:J(b?
//count++; V\]" }V)"
//if(count>4) p(F" /
// siteStop(); /) 4GSC}Gg
} IA&L]
Wg`AZ=t
tK(g-u0N`(
System.err.println("文件下载结束！"); ^|!I+
} c{+AJ8
catch(Exception e){e.printStackTrace ();} j*v40mXl`2
} ? "/ fPV-
m#vL*]c}
69K{+|
//获得文件长度 N|g;W
public long getFileSize() )~J>X{hy
{ !7bw5H
int nFileLength = -1; ?, r~=
try{ )D&M2CUw"f
URL url = new URL(siteInfoBean.getSSiteURL()); R6-n IY,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N6OMYP1
httpConnection.setRequestProperty("User-Agent","NetFox"); [,RI-#n
&MZ$j46
y&m0Lz53Z
int responseCode=httpConnection.getResponseCode(); $~0Q@):
if(responseCode>=400) N==ZtKj F
{ xo}b= v
processErrorCode(responseCode); D]a:@x`+Bz
return -2; //-2 represent access is error wxg^Bq)D*R
} M 3 '$[
l%ayI
$rF=_D6
String sHeader; eN?Y7
TL$EV>Nr
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for(int i=1;;i++) `;|5
{ :<Y}l-x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [D-Q'"'A
//Utility.log(in.readLine()); 9^"b*&>P
sHeader=httpConnection.getHeaderFieldKey(i); g"s$}5{8:
if(sHeader!=null) ,#FLM`
{ 9E2j!
if(sHeader.equals("Content-Length")) acP+3u?r
{ :F,O
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); SzwQOs*
break; D\w h;r
} Zv11uH-C
} Ji1Pz)fq
else *L6PLe
break; PWRy7d
} GZS1zTwBL
} T{qTj6I
catch(IOException e){e.printStackTrace ();} H1GRMDNXOA
catch(Exception e){e.printStackTrace ();} Jj~EiA
X"gCRn%tn
A[IL H_w
Utility.log(nFileLength); '{I_\~*
=deMd`=J
TD[EQ
return nFileLength; YjF|XPv+ l
} ^,l_{
?Xdak|?i
)VL96did
//保存下载信息（文件指针位置） !Fo*e
private void write_nPos() NNhL*C[_7
{ Xs&TJ8a
try{ Pq*s{
output = new DataOutputStream(new FileOutputStream(tmpFile)); V.ht, ~l
output.writeInt(nStartPos.length); Zwcy4>8
for(int i=0;i<nStartPos.length;i++) }i{sg#
{ dzK{ Z
// output.writeLong(nPos); yR{x}DbG
output.writeLong(fileSplitterFetch.nStartPos); 7n]65].t
output.writeLong(fileSplitterFetch.nEndPos); Uv YF[@
} 7Dnp'*H
output.close(); )jWOP,|
} (,^*So/
catch(IOException e){e.printStackTrace ();} O}9KJU
catch(Exception e){e.printStackTrace ();} }$MN|s
} r`)L~/
\s3]_1F;t
+*\X]06
//读取保存的下载信息（文件指针位置） JN^&S
private void read_nPos() SN4Q))dAU
{ +`7KSwa
try{ xq6cKtSv
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,+`61J3W
int nCount = input.readInt(); 'r(1Nj
nStartPos = new long[nCount]; -a*K$rnB
nEndPos = new long[nCount]; DD" $1o"
for(int i=0;i<nStartPos.length;i++) 1/p*tZP8i
{ ??TMSH
nStartPos = input.readLong(); QL6C,#6
nEndPos = input.readLong(); Kp+CH7I*
} f.24:Dw,
input.close(); ~GE$myUT\p
} E?(xb B
catch(IOException e){e.printStackTrace ();} o=FE5"t
catch(Exception e){e.printStackTrace ();} 85EQ5yY
} #%J5\+ua
OD']:
$$:ZX
private void processErrorCode(int nErrorCode) tXJUvish
{ BCe_@
System.err.println("Error Code : " + nErrorCode); aP'"G^F
} ARcv;H 5
8|E'>+ D_-
n wI!O
//停止文件下载 ih?^t(i
public void siteStop() n|GaV
{ TO%dw^{_`
bStop = true; hhoEb(BA
for(int i=0;i<nStartPos.length;i++) f+rz|(6vs{
fileSplitterFetch.splitterStop(); GGhM;%H_99
6}FO[
%OgS^_tu
} fgihy
} FU=w(< R;
//负责部分文件的抓取 wts=[U`(
**FileSplitterFetch.java uEc<}pV
*/ - 0?^#G}3}
package NetFox; g$dsd^{O7
JG{j)O|L
.z13 =yv
import java.io.*; 52upoU>}2
import java.net.*; f|u#2!7
7JSNYTH
eNiaM6(J
public class FileSplitterFetch extends Thread { jA#/Z
?\8?%Qk
j~j\\Y
String sURL; //File URL hHqh{:q{v
long nStartPos; //File Snippet Start Position G,;,D9jO7
long nEndPos; //File Snippet End Position vkLC-Mzm<
int nThreadID; //Thread's ID s,a}?W
boolean bDownOver = false; //Downing is over ^5r9 5
boolean bStop = false; //Stop identical sgE-`#
FileAccessI fileAccessI = null; //File Access interface s+:=I e
fO#vF.k%
LJoGpr8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e8'wG{3A
{ AIA6yeaU
this.sURL = sURL; 7)h[Zy,A
this.nStartPos = nStart; ?f/n0U4w
this.nEndPos = nEnd; ;-UmY}MU
nThreadID = id; 9n}p;3{f
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !|c|o*t{
} +2 Af&~T
_)]CzBRq\6
!x'/9^i~v
public void run() |lv|!]qAma
{ XD"_Iq!
while(nStartPos < nEndPos && !bStop) G%d (
{ ioPUUUb)
yoAfc
|p$spQ
try{ ePIiF_X
URL url = new URL(sURL); _=|vgc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l7De6A"
httpConnection.setRequestProperty("User-Agent","NetFox"); 6"dD2WV/
String sProperty = "bytes="+nStartPos+"-"; klUQkz |<a
httpConnection.setRequestProperty("RANGE",sProperty); eW|^tH
Utility.log(sProperty); O{ /q-~_
JI vo_7{
F[ewn/]n
InputStream input = httpConnection.getInputStream(); NWxUn.Gy9
//logResponseHead(httpConnection); OT&k.!=
Y2'cs~~$Ce
Ali9pvE
byte[] b = new byte[1024]; 7t.!lh5G%
int nRead; ,]b~t0|B
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k%^lF?_0I
{ h;3cd0
nStartPos += fileAccessI.write(b,0,nRead); 3j3N!T9
//if(nThreadID == 1) &HSq(te
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vzmc}y G
} x`6<m!d`
-\#0]F:-
r_;9'#&'
Utility.log("Thread " + nThreadID + " is over!"); }<'5 z qS
bDownOver = true; F5o+kz$;
//nPos = fileAccessI.write (b,0,nRead); TwgrRtj'
} } (!EuLL
catch(Exception e){e.printStackTrace ();} }%D^8>S
} LY+|[qka
} `Qeg
VE8;sGaJ
*-xU2
//打印回应的头信息 fw[y+Bi& ?
public void logResponseHead(HttpURLConnection con) Qyy.IPTP
{ kY'T{Sm1^
for(int i=1;;i++) LiKxq=K
{ `mN4_\]
String header=con.getHeaderFieldKey(i); \rPbK+G.
if(header!=null) O(_[ayE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [|l?2j\
Utility.log(header+" : "+con.getHeaderField(header)); }CfqG?)
else IIyI=WlpG
break; 6S~sVUL9`
} V%Sy"IG
} VU@9@%TN
|<O9Sb_
t:fFU1x
public void splitterStop() Q?X>E3=U
{ @$T 9Ll
bStop = true; *&f$K1p
} D.mHIsX6\
/JT#^Y
a.z;t8
} @/k@WhFZ
5ms""LD/
S%`0'lzzj
/* GH[wv<
**FileAccess.java ~}<DG1!
*//文件访问(定位，写) H9CS*|q6r
package NetFox; B,{K*-7)MX
import java.io.*; be +4junf
+a*tO@HG
PiA0]>
public class FileAccessI implements Serializable{ Q~T$N
{P*m;a`}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :^(>YAyHj^
RandomAccessFile oSavedFile; DY^;EZ!hb
long nPos; QV\eMuNy
` Jdb;
~s5SZK*
public FileAccessI() throws IOException RSo&(Uv
{ %plo=RF
this("",0); <n#DT
} *BR^U$,e
]KmO$4
"&3h2(#%
public FileAccessI(String sName,long nPos) throws IOException ~ yX2\i"
{ KGg3 !jY
oSavedFile = new RandomAccessFile(sName,"rw"); e;(0(rI
this.nPos = nPos; y99mC$"Ee`
oSavedFile.seek(nPos); #B\"'8#
} !50[z:
& \f{E\A#
$*?,#ta
public synchronized int write(byte[] b,int nStart,int nLen) )6aAB|
{ ?Ec7" hK
int n = -1; f`Fi#EKT
try{ zE_i*c"`
oSavedFile.write(b,nStart,nLen); D gaMO,
n = nLen; ,I,\ml
} mWvl38
catch(IOException e) X*\J_
{ #{\%rWnCm
e.printStackTrace (); JeE;V![
} dN$Tf
R47\Y
)KAEt.
return n; rh^mJUh
} r3PT1'P?L
cMOyo<F#^=
LSRk7'0
} b1($R[
7"C$pm6
j}C}:\-fY
/* Ct>GYk$
**SiteInfoBean.java ruy}/7uf
*/ \*<d{gZ~
package NetFox; >m$ 1+30X
&e!7Z40w@&
SBS3?hw
public class SiteInfoBean { bR)(H%I
.*)2SNH
a8UwhjFO
private String sSiteURL; //Site's URL ?pd8w#O
private String sFilePath; //Saved File's Path :\o {_
private String sFileName; //Saved File's Name VFys.=
private int nSplitter; //Count of Splited Downloading File H7DJ~z~J
>o=-$gz`
#}y2)g
public SiteInfoBean() BGX.U\uc
{//nSplitter的缺省值为5 sdo[D
//default value of nSplitter is 5 nX`u[ks
this("","","",5); ]@u6HH~^
} RtM8yar+sn
EU+S^SyZi
=aTv! 8</
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1waTTT?"Ho
{ L}pt)w*V1j
sSiteURL= sURL; 3zcU%*
sFilePath = sPath; \r+8qC[,
sFileName = sName; XY3v_5~/1F
this.nSplitter = nSpiltter; Xx>X5Fy
OL^l 3F
,]d/Q<
} @W"KVPd
z+n,uHs
ybKWOp:O
public String getSSiteURL() lE(a%'36
{ W~7A+=&
return sSiteURL; LF& z
} oc>{?.^
,1+y/{S
)`O~f_pIC
public void setSSiteURL(String value) #;2n;.a
{ 8p:e##%
sSiteURL = value; CmoE_8U>
} v: OR
F}/S:(6LF2
o9dY9o+Z
public String getSFilePath() abfW[J
{ /Y2}a<3&0
return sFilePath; U ^5Kz-5.
} fy@<&U5rg
oUQ,61H
^Xq 6:
public void setSFilePath(String value) %UERc{~o*,
{ e9U9Uu[
sFilePath = value; ?Yth0O6?sb
} $m-2HhqZ
(Hb:?(
4i(JZN?
public String getSFileName() UKT%13CO4U
{ FWG6uKv
return sFileName; 3@$,s~+ 3
} VoWNW
jk[1{I/
_n50C"X=&(
public void setSFileName(String value) sg3OL/"
{ T^k7o^N>
sFileName = value; 9Hb6nm
} 'O_3)x5
!C3MFm{B
|es?;s'
public int getNSplitter() PuA9X[=
{ D"2&P^-
return nSplitter; BMG3|N^
} xg;+<iW
YSic-6z0Ms
lJ}_G>GJ
public void setNSplitter(int nCount) DpvI[r//'*
{ %Q fO8P
nSplitter = nCount; e]$}-i@#
} 1Vrh4g.l
} QLvHQtzwX
?R$F)g7<
qzKdQ&vO
/* 2db3I:;E
**Utility.java ZQ%'`q\c
*/ U4C 9<h&
package NetFox; 2a`o &S
L\xk:j1[
Ez fN&8E
public class Utility { vyK7I%T'R
gM u"2I5
t!W(_8j
public Utility() CUBEW~X}M
{ :OhHb#D
KWowN;
e478U$
} >>t@}F)
Eg#K.5hJ
//线程睡眠 wnEyl[ac
public static void sleep(int nSecond) "$+Jnc!!
{ lm-dW'7&
try{ P3x= 8_#
Thread.sleep(nSecond); ' V^6XI
} Q Nh|Wz
catch(Exception e) 4ew" %Cs*
{ N~goI#4
e.printStackTrace (); (_mnB W
} N`5,\TR2f
} 'g=
cdl&9-}
//日志 Zw5Ni Xj
public static void log(String sMsg) F4}]b(L
{ Z<1FSk,[
System.err.println(sMsg); "U>JM@0DNm
} 4:$4u@
-Ta9 pxZk
8dZSi
public static void log(int sMsg) LsqA**=
{ iNtaDX|%/
System.err.println(sMsg); B%)%
} O`x;,6Vr
} 1PVtxL?1P
xW)2<m6C&
=9O^p@Q#W
/* WM7oM~&{6
**TestMethod.java 4B =7:r
*/ nm5cpnNl
package NetFox; ~dgDO:)
?I_s0k I
%GjM(;Tk
public class TestMethod { p{amC ;cI$
=9'RM>
9YIM'q>`v
public TestMethod() 8uc1iB
{ ///xx/weblogic60b2_win.exe +Mo9kC
try{ ov`h
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p Dx1z|@z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &=Ar
SiteFileFetch fileFetch = new SiteFileFetch(bean); Z&Pg"a?\
fileFetch.start(); E4`N-3
} X@+{5%
catch(Exception e){e.printStackTrace ();} 2,$8icM
Cc+t}"^
l2zFKCGF(
} @Owb?(6?
cs,N <|
+%zAQeb
public static void main(String[] args) BZ94NOOdw
{ fxgPhnaC>
new TestMethod(); 4ni<E*
} #C~+JL
} rq8K_zp
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