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)); ]TBtLU3
} Bug}^t{M
for(int i=0;i<nEndPos.length-1;i++) YYE8/\+B.
{ Z@,PZ
nEndPos = nStartPos[i+1]; {!}F :~*r
} w^])(
nEndPos[nEndPos.length-1] = nFileLength; G_M:0YI@
} (#bp`Kih
} l{6` k<J(
=,4 '"
K6v $#{$6
//启动子线程 aM{@1mBm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Seq]NkgY
for(int i=0;i<nStartPos.length;i++) i#RElH
{ P}hY{y'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z.:<TrN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q^lQi\[
nStartPos,nEndPos,i); kOAY@a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UXwB$@8
fileSplitterFetch.start(); B)rr7B
} PW*;Sp
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,rZn`9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5:%..e`T
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B6ed,($&
nEndPos = " + nFileLength); g=xv+e
// fileSplitterFetch[nPos.length-1].start(); au~]
9p2>`L
6Lg!Lodu
//等待子线程结束 @A2/@]HBm
//int count = 0; )WVItqQKV
//是否结束while循环 VFl 1 f
boolean breakWhile = false; B;GxfYj
L19MP
x2C/L
while(!bStop) =t3vbV
{ N.0HfYf
write_nPos(); Ht|",1yr+
Utility.sleep(500); $N;"}Gz
breakWhile = true; >*`>0Q4y
?dsf@\
3}B5hht"D
for(int i=0;i<nStartPos.length;i++) ADYx.8M|9i
{ 8cK\myn.
if(!fileSplitterFetch.bDownOver) =w^TcV
{ lf%b0na?r
breakWhile = false; >f\zCT%cf
break; -BA"3 S
} fJLf7+q
} #\pP2
if(breakWhile) b JfD\
break; # 0GGc.
I9}+(6
:tMre^oP
//count++; 3P//H88LY
//if(count>4) [d4,gEx`Q\
// siteStop(); ORowx,(hX
} 4}Q O!(
'7xxCj/*
':l"mkd+`
System.err.println("文件下载结束！"); f?%qUD_#
} `'p`PyMt`
catch(Exception e){e.printStackTrace ();} (2z%U
} m|]j'g?{}(
rDVgk6
}RcK_w@Jx)
//获得文件长度 (8CCesy&
public long getFileSize() \!^i;1h0c3
{ m[Z6VHn
int nFileLength = -1; uR#'lb`3
try{ ^^G-kg
URL url = new URL(siteInfoBean.getSSiteURL()); .OmQ'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?k{|Lk
httpConnection.setRequestProperty("User-Agent","NetFox"); L5Urg*GNL
-<Jq
4~O6$;!|~
int responseCode=httpConnection.getResponseCode(); Zc-#;/b3T
if(responseCode>=400) GAv)QZyV$
{ S8O)/Sg=
processErrorCode(responseCode); 9>N\sOh
return -2; //-2 represent access is error u4:\UC'
} $ !v}xY
tM&n3MWQ
\n#]%X5c
String sHeader; }0QN[$H!
f hQy36i@
'pan9PW
for(int i=1;;i++) }>V/H]B
{ MZT6g.ny
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); NMXnrvS&
//Utility.log(in.readLine()); hUVk54~l
sHeader=httpConnection.getHeaderFieldKey(i); i{8]'fM
if(sHeader!=null) |~SE"
{ I>{!U$
if(sHeader.equals("Content-Length")) H(G!t`K
{ %a5t15 9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tXt:HVN
break; 7))\'\
} -b cG[W3
} \a"i7Caa
else oEJaH
break; ]nUR;8
} cTM$ZNin
} vYDSu.C@a
catch(IOException e){e.printStackTrace ();} &vCeLh:s
catch(Exception e){e.printStackTrace ();} ]/Vh{d|I&
);nz4/V
kI%peb?
Utility.log(nFileLength); UP\C"\
OU!nN>ln
0<g<GQ(E
return nFileLength; & g:%*>7P
} U^[<
%y>+1hakkX
=_[2n?9y
//保存下载信息（文件指针位置） ~LbS~_\C=
private void write_nPos() O#Z/+\U
{ gmY/STN
try{ a:A n=NA
output = new DataOutputStream(new FileOutputStream(tmpFile)); IAf$]Fh
output.writeInt(nStartPos.length); .`,F
for(int i=0;i<nStartPos.length;i++) Uo2+:p
{ KbAR_T1n
// output.writeLong(nPos); &y70
output.writeLong(fileSplitterFetch.nStartPos); L\YKdUL
output.writeLong(fileSplitterFetch.nEndPos); 8h|M!/&2
} Bz+.Qa+
output.close(); 0#QKVZq2>
} p%F8'2)}
catch(IOException e){e.printStackTrace ();} ;hwzYXWF
catch(Exception e){e.printStackTrace ();} !tU'J"Zy
} !6HuFf
PL@~Ys0
FEF"\O|Q
//读取保存的下载信息（文件指针位置） i^*M^P3m
private void read_nPos() /s:w^g~
{ &|b4\uj9
try{ Q&xjF@I
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `FZF2.N
int nCount = input.readInt(); %zzYleJ!]
nStartPos = new long[nCount]; kn}zgSO
nEndPos = new long[nCount]; o@9+mM"B)
for(int i=0;i<nStartPos.length;i++) g:_hj_1Y M
{ }B0sC%cm
nStartPos = input.readLong(); rfs(#
nEndPos = input.readLong(); >GXXjAIu/
} /Pvk),ca
input.close(); :&qhJtGo
} k#C f})
catch(IOException e){e.printStackTrace ();} GAw(mH*
catch(Exception e){e.printStackTrace ();} 2ev*CX6.
} =q+R
BX[~%iE
edijfhn
private void processErrorCode(int nErrorCode) R,Fgl2
{ %X>FVlPm
System.err.println("Error Code : " + nErrorCode); gO='A(Y
} ]tB@kBi "
U\jb"
Fu7M0X'p
//停止文件下载 fN)x#?
public void siteStop() T|;@T^
{ R)oB!$k
bStop = true; *%\mZ,s"
for(int i=0;i<nStartPos.length;i++) S/4r\6
fileSplitterFetch.splitterStop(); jvHFFSK
NQX>Qh 2
?[)yGRzO2
} Kb&V!#o)
} vvq/
//负责部分文件的抓取 sb^mLH] 3
**FileSplitterFetch.java ZyI$M3{J
*/ +j{Y,t{4
package NetFox; eY,O@'"8`
BLn_u,3
?59'dGnz_
import java.io.*; l%~lz[
import java.net.*; @g-G =Ba
yK1ie
PcC/_+2
public class FileSplitterFetch extends Thread { nPFwPk8=M
"R[l ZJ@
E]I$}>k
String sURL; //File URL j*400
long nStartPos; //File Snippet Start Position ^lj7(
long nEndPos; //File Snippet End Position $dQIs:
int nThreadID; //Thread's ID mR%FqaN_
boolean bDownOver = false; //Downing is over }D*yr3b
boolean bStop = false; //Stop identical <*(^{a.O
FileAccessI fileAccessI = null; //File Access interface :,S98z#
oC*=JJe,
gL3iw!7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BT,b-= ;J-
{ \X|sU:g
this.sURL = sURL; h|bT)!|
this.nStartPos = nStart; Kqg!,Sn|
this.nEndPos = nEnd; eC! #CK
nThreadID = id; 3mO;JXd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c_.-b=zm
} ""% A'TZ
4)kG-[#
.Z\Q4x#!Z
public void run() w1`QIv
{ T2FE+A]n9
while(nStartPos < nEndPos && !bStop) g(Yb^'X/
{ ,Na^%A@TJ
AjkW0FB:1
V'DA[{\*
try{ "OmD@ EMT
URL url = new URL(sURL); 9Uf j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DinPxtT?a
httpConnection.setRequestProperty("User-Agent","NetFox"); 9\JQ7$B
String sProperty = "bytes="+nStartPos+"-"; SA;#aj}rV
httpConnection.setRequestProperty("RANGE",sProperty); R>/NE!q
Utility.log(sProperty); ,q#0hy%5/
]:ZdV9`
upy\gkpnGO
InputStream input = httpConnection.getInputStream(); i7*EbaYzUO
//logResponseHead(httpConnection); IiJZ5'{
lg$zGa?
y<:<$22O
byte[] b = new byte[1024]; z>m=h)9d~
int nRead; ^D{lPu 3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -/P\"c
{ pH@]Y+W
nStartPos += fileAccessI.write(b,0,nRead); ][&9]omB
//if(nThreadID == 1) LWfqEL -
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !bnyJA
} BU|#e5
O|kOI?f
T,%j\0
Utility.log("Thread " + nThreadID + " is over!"); K`g7$r)U[
bDownOver = true; n.}E5%qK
//nPos = fileAccessI.write (b,0,nRead); Cbm\h/PXl
} p-GAe,2q
catch(Exception e){e.printStackTrace ();} T;5r{{
} )%d*3\Tsd
} PG~$D];
CW&.NT
eHiy,IN
//打印回应的头信息 47K1$3P
public void logResponseHead(HttpURLConnection con) 9(4&KZpK
{ ~;]W T
for(int i=1;;i++) nkfZiyx
{ eWJ`$"z
String header=con.getHeaderFieldKey(i); *{ {b~$
if(header!=null) kM8{Cw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v\tEVhm
Utility.log(header+" : "+con.getHeaderField(header)); g%[c<l9
else #_93f |
break; 06q(aI^Ch@
} -G7TEq)
} s$D ^>0
7*5Z
Jg}K.1Hs
public void splitterStop() T~0k"uTE
{ ;!!n{l$r'
bStop = true; (xHf4[[u
} 9H-|FNz?c
z`UhB%-?
>TkE~7?l
} pi<TFe@eG
anMF-x4/*q
jRSUp E8
/* }|u4 W?H
**FileAccess.java Qv,"($n\
*//文件访问(定位，写) y*pUlts<
package NetFox; l*\y
import java.io.*; aI^/X{d
}G4ztiuG
}XO K,Hw
public class FileAccessI implements Serializable{ /='. 4v
]vWKR."4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 VXIP0p@
RandomAccessFile oSavedFile; 2EZb )&Q
long nPos; Y2o?gug
3b'QLfU&#
gL_Y,A~Q{
public FileAccessI() throws IOException 3 @ak<9&
{ 'u4<BQVV[
this("",0); }by;F9&B
} ks$JP6
u/cg|]x&T
q\m2EURco
public FileAccessI(String sName,long nPos) throws IOException $,+O9Et
{ ),G=s Oo
oSavedFile = new RandomAccessFile(sName,"rw"); #wL
this.nPos = nPos; OQW#a[=WQ
oSavedFile.seek(nPos); T}V!`0vKw
} M`rl!Ci#
91=OF*w
n2)q}_d
public synchronized int write(byte[] b,int nStart,int nLen) 3s/H2fz
{ fFb_J`'ue
int n = -1; 3;S,3
try{ Tb3J9q+ya
oSavedFile.write(b,nStart,nLen); O+y-}7YX
n = nLen; J5^'HU3
} &boOtl^
catch(IOException e) 8GvJ0Jq}U
{ rM'=_nmi
e.printStackTrace (); 5R(/Uiv3F
} \,u_7y2 c
u%w`:v7Yo(
{&jb5-*f
return n; v?KC%
} M$Zcn#A
bGc~Wr|
Vx~,Uex0+
} O3I8k\`
uc;8 K,[t
n4}Br;%
/* tmQH|'>>
**SiteInfoBean.java gbH<]?
*/ xlhG,bb7
package NetFox; $GlWf
b )B? F
{q"OM*L(
public class SiteInfoBean { zT!drq:x
W[Ls|<Q
{phNds%
private String sSiteURL; //Site's URL qWQ/'M
private String sFilePath; //Saved File's Path e" St_z(
private String sFileName; //Saved File's Name j'A_'g'^
private int nSplitter; //Count of Splited Downloading File dBz/7&Q
7=;R& mqC
Z'"tB/=W
public SiteInfoBean() :]\([Q+a
{//nSplitter的缺省值为5 a(l29>
//default value of nSplitter is 5 _d5QbTe
this("","","",5); "wNJ
} 9I}-[|`u
Zl^\Q=*s
etTn_v
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) r>o63Q:
{ D)L+7N0D~
sSiteURL= sURL; [ucpd
sFilePath = sPath; '.:z&gSqx0
sFileName = sName; `{dm;j5/y
this.nSplitter = nSpiltter; XD.)Dl8
wne,e's}
LDPUD'
} `aciXlqIF
Lm%:K]X
'<"s \,
public String getSSiteURL() G3Z)Z)N
{ `@`CG[-9
return sSiteURL; KV(Q;~8"X
} >CHrg]9
U~:-roQ(\
17%Mw@+
public void setSSiteURL(String value) hb}+A=A=+
{ g:hjy@ w
sSiteURL = value; 5>[u `
} ?8'*,bK
~"nxE
.+$Q<L
public String getSFilePath() <3LbNFP
{ 45@^L's
return sFilePath; x(1:s|Uyp{
} I>W=x'PkLn
6 (]Dh;gC
_852H$H\
public void setSFilePath(String value) EV]1ml k$
{ y3@H/U{
sFilePath = value; s~^5kgPA
} ;r<^a6B
F1*>y
dYJ(!V&
public String getSFileName() y [}.yyye
{ IG2r#N|C#
return sFileName; F3On?x)
} Te"ioU?.
$a.JSXyxL
v[1aWv:
public void setSFileName(String value) Kp%2k^U
{ G<65H+)M\
sFileName = value; >qnko9V
} wW>A_{Y
d;boIP`M;
xF!,IKlBBp
public int getNSplitter() LSL/ZvSP
{ akp-zn&je
return nSplitter; =$'6(aDH
} f6hnTbJ
ldU?{o:\s
h4fJvOk|!
public void setNSplitter(int nCount) p`olCp'
{ lXW%FH6c+
nSplitter = nCount; c"f-3kFv
} 6'k<+IR
} bRFLcM
y%"{I7!A
XP!S$Q]D
/* mE+*)gb:Rd
**Utility.java ~Y^+M*
*/ Sc]B#/~B
package NetFox; ?WGA?J %2
"H'B*vc-
J!dm-L
public class Utility { D+lAhEN
~~D{spMVO
ZgTW.<.%2
public Utility() {'7B6
{ - YEZ]:"
ha]VWt%}
*& BQTZ6
} xQ f*
BtkOnbz8X
//线程睡眠 Ri<u/ ]oR"
public static void sleep(int nSecond) )1?y 8_B
{ 3Z>Ux3[
try{ cuax;0{%
Thread.sleep(nSecond); |mZxfI
} Ytn9B}%o
catch(Exception e) KI"#f$2&
{ Z9v31)q(
e.printStackTrace (); 01 }D,W`
} hNC&T`.-~B
} g|o,uD
S|Q@:r"
//日志 P_F30x(
public static void log(String sMsg) lU8l}Ndz"
{ (p"%O
System.err.println(sMsg); 4>wP7`/+y
} R$R*'l
!z\h|wU+
\1k79c
public static void log(int sMsg) Hus)c3Ty7
{ '{cIAw/"n
System.err.println(sMsg); E^B'4
} L^1NY3=$
} R)c?`:iUB
A#e%^{q$
Tf>bX_L?
/* XY5K%dMU
**TestMethod.java 'p^t^=dQ
*/ \[;0KV_
package NetFox; 5?f ^Rz
Akq2 d;
NDN7[7E
public class TestMethod { nGC/R&
^}RCoE
%Hu5K>ZNYp
public TestMethod() VF+KR*
{ ///xx/weblogic60b2_win.exe Sj3+l7S?
try{ a1T'x~ '
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aS>u,=C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D(~U6SR
SiteFileFetch fileFetch = new SiteFileFetch(bean); %Tfbsyf%f
fileFetch.start(); ]=\].% >
} H%[eV8
catch(Exception e){e.printStackTrace ();} C"y(5U)d
dn&s*
{y)=eX9
} CT&|QH{
b!+hH Hv:
-M\<nx
public static void main(String[] args) 4j-Xi
{ x[cL Bc<
new TestMethod(); n'"/KS+_
} R|'ybW'Y
} AzPu)
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