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)); }=hoATs
} X^D9)kel
for(int i=0;i<nEndPos.length-1;i++) +%Yc4
{ mp,e9Nd;
nEndPos = nStartPos[i+1]; N+M&d3H`
} n<:d%&^n
nEndPos[nEndPos.length-1] = nFileLength; vaRwhE:
} "'!%};
} Dw`m>'J0
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R==cz^#
//启动子线程 Ejms)JK+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I\upnEKKzZ
for(int i=0;i<nStartPos.length;i++) vA;F]epr!
{ ~$4.Mf,u
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aGe(vQPi9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q[7d7i/r6
nStartPos,nEndPos,i); `8(h,aj;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o? i.v0@!K
fileSplitterFetch.start(); v]T(zL|
} 5Y Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1_NG+H]x9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q*:h/Lhb&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vV.~76AD5
nEndPos = " + nFileLength); >4/L-y+
// fileSplitterFetch[nPos.length-1].start(); :@ E1Pun?
qggk:cN1
Dk`4bYK
//等待子线程结束 c',:@2R
//int count = 0; &'(a$S>v
//是否结束while循环 Q+d.%qhc
boolean breakWhile = false; [2'm`tZL
v1nQs='
Fi'M"^:r{
while(!bStop) (]Ye[j^"7
{ OwA~(
write_nPos(); (9}eF)+O
Utility.sleep(500); @yt2_
breakWhile = true; RM&H!E<#
Y=a v8Y|`
;tp]^iB#
for(int i=0;i<nStartPos.length;i++) sLG>>d3R1
{ 'B3Wza.
if(!fileSplitterFetch.bDownOver) y~ _za(k
{ q#99iiG1
breakWhile = false; JOrELrMx
break; 5@czK*5
} N^\2 _T
} u m:0y,
if(breakWhile) +9zJlL^A%
break; VW9>xVd4
UZje>.~?
{}_Nep/;
//count++; oWp}O?
//if(count>4) ZU|6jI}
// siteStop(); dP$8JI{
} )'[x)q
"{A*(.
;8*XOC;[
System.err.println("文件下载结束！"); *N-;V|{
} nn@^K6
catch(Exception e){e.printStackTrace ();} U!&_mD# c
} UzgA26;
v/R[?H)
b0@>xT
//获得文件长度 b4Z`y8=
public long getFileSize() R"U/RS
{ &yxNvyA[u
int nFileLength = -1; AH2_#\
try{ 'tb(J3ZP
URL url = new URL(siteInfoBean.getSSiteURL()); ;)(Sdf[P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e1 x^PT
httpConnection.setRequestProperty("User-Agent","NetFox"); `^7:7Wr]=
wMb)6YZs
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int responseCode=httpConnection.getResponseCode(); erx5j\
if(responseCode>=400) ~;M)qR?]W
{ gjj 93
processErrorCode(responseCode); D|@bGN
return -2; //-2 represent access is error T'ED$}N>~
} 0]AN;
)0#j\B
D##+)`dK
String sHeader; 2+?T66 g
sm 's-gD
G2.|fp_}pG
for(int i=1;;i++) pheE^jUr
{ GE1i+.+-.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /g_9m
//Utility.log(in.readLine()); %#~((m1
sHeader=httpConnection.getHeaderFieldKey(i); n*4lz^LR
if(sHeader!=null) oZTgN .q
{ 4k8*E5cx
if(sHeader.equals("Content-Length")) <9P4}`%)3
{ M|\^UF2e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o#qH2)tb
break; CRH{E}>
} #6Jc}g<?g
} t, U) ~wi
else *GQDfs`m
break; pzp,t(%j
} `79[+0hL'
} \K}-I
catch(IOException e){e.printStackTrace ();} d1v<DU>M
catch(Exception e){e.printStackTrace ();} L}'Yd'
&&=[Ivv
hAm/mu
Utility.log(nFileLength); %2f//SZ:
NJtQx2Sd'H
wV(AT$
return nFileLength; _7U]&Nh99
} X1+wX`f
'Qa5n\HX$
eD%HXGe
//保存下载信息（文件指针位置） 96d~~2p
private void write_nPos() 1y J5l,q
{ (Uk>?XAr
try{ xc9YM0B&
output = new DataOutputStream(new FileOutputStream(tmpFile)); @@I7$*
output.writeInt(nStartPos.length); s~*}0-lS
for(int i=0;i<nStartPos.length;i++) 9Ycn0
{ xJ{_qP
// output.writeLong(nPos); vY6oVjM
output.writeLong(fileSplitterFetch.nStartPos); XZ`:wmc|
output.writeLong(fileSplitterFetch.nEndPos); 3jjMY
} r-}-C!
output.close(); 0}{'C5
} 7 8Vcu'j&_
catch(IOException e){e.printStackTrace ();} hi ~}
catch(Exception e){e.printStackTrace ();} o*">KqU`b
} Dj i^+;"&
? B@&#E!/f
9mlIbEAb
//读取保存的下载信息（文件指针位置） Tc6:UF
private void read_nPos() ='Q{R*u
{ n]Zk;%yL
try{ 6i.gyD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Mp~y0e
int nCount = input.readInt(); kH'p\9=
nStartPos = new long[nCount]; y<pnp?x4
nEndPos = new long[nCount]; q2hFOm
for(int i=0;i<nStartPos.length;i++) %SrM|&[
{ j9d!yW
nStartPos = input.readLong(); #]CFA9z
nEndPos = input.readLong(); +Y}V3(w9X
} `ltN,?/
input.close(); <Mx0\b!
} [}OgSP9i
catch(IOException e){e.printStackTrace ();} :_ROJ
catch(Exception e){e.printStackTrace ();} %f j+70
} {%C*{,#+8q
G?AG:%H%
[U>@,BH
private void processErrorCode(int nErrorCode) 8"%RCE
{ !M7<BD};
System.err.println("Error Code : " + nErrorCode); \\,f{?w
} n`ViTwd]MQ
*)<B0SjT
1|{bDlmt
//停止文件下载 OoBCY-gj*
public void siteStop() nOb?-rR
{ ZE?f!ifp
bStop = true; ~gE:-
for(int i=0;i<nStartPos.length;i++) -`+<{NHv\
fileSplitterFetch.splitterStop(); BecPT
:u6JjW[a)
!z 53OT!
} k|vI<:'p,
} iDoDwq!l_
//负责部分文件的抓取 ?YQPlv:<o.
**FileSplitterFetch.java a,|?5j9,P
*/ :XG;ru%i
package NetFox; 3*ixlO:qGk
26I
foRD{Hx
import java.io.*; Os&n
import java.net.*; vAb^]d
FOwnxYGVf
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public class FileSplitterFetch extends Thread { c$:1:B9\
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String sURL; //File URL z'7[Tie
long nStartPos; //File Snippet Start Position {2&m`Dbm
long nEndPos; //File Snippet End Position JIm4vS
int nThreadID; //Thread's ID T!RT<&
boolean bDownOver = false; //Downing is over (#D*Pl
boolean bStop = false; //Stop identical OFk8>"|
FileAccessI fileAccessI = null; //File Access interface gU&%J4O
'G&{GVbXY
r%@Lej5+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \f:z+F!6R
{ P 1XK*GZ
this.sURL = sURL; m<rhIq
this.nStartPos = nStart; NGC,lv
this.nEndPos = nEnd; Wy .IcWK
nThreadID = id; &;i "P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WWKvh
} ,Lpixnm]
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0 B@n{PvR0
public void run() {q%Sx*k9[
{ \1"'E@+
while(nStartPos < nEndPos && !bStop) /E;y,o75
{ d}'U?6ob
DdQ;Q5|
r]@0eb
try{ /ID3s`D)
URL url = new URL(sURL); 7c|bc6?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \u,}vppz
httpConnection.setRequestProperty("User-Agent","NetFox"); =Prb'8 W
String sProperty = "bytes="+nStartPos+"-"; : _e#
httpConnection.setRequestProperty("RANGE",sProperty); Byl^?5
Utility.log(sProperty); _VE^/;$"l
bmgncwlz
$+JS&k/'m
InputStream input = httpConnection.getInputStream(); U>Ld~cw
//logResponseHead(httpConnection); K6/@]y%Wr
r3E!dTDWq
G!w"{Bk?9
byte[] b = new byte[1024]; /1N6X.Zb
int nRead; uvDzKMw~R
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &QRE"_g
{ Q;11N7+
nStartPos += fileAccessI.write(b,0,nRead); c'uhK8|
//if(nThreadID == 1) Hy.AyU|L
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~Q{QM:k
} !oPq?lW9
N`iwC!
PZxAH9 S?
Utility.log("Thread " + nThreadID + " is over!"); -fhN"B)
bDownOver = true; L`f^y;Y.
//nPos = fileAccessI.write (b,0,nRead); U,#yqER'r
} > fnh+M
catch(Exception e){e.printStackTrace ();} *IgE)N>
} De7Ts
} =4V&*go*\
ZkL8e
dQoYCS}IaV
//打印回应的头信息 4[Z\ ?[
public void logResponseHead(HttpURLConnection con) k@zy
{ v+p{|X-
for(int i=1;;i++) d->|EJP
{ ]Chj T}
String header=con.getHeaderFieldKey(i); `&\Q +W
if(header!=null) X%z }VA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +$4(zPs@
Utility.log(header+" : "+con.getHeaderField(header)); JB!:JML
else sn7AR88M;
break; |*Z$E$k:
} R_M?dEtE>
} b0iSn#$
S$KFf=0
>U F
public void splitterStop() f#+el y
{ 3bO(?l`3h
bStop = true; BA\/YW @
} `:N# 'i
.MO\uh0N
" \I4u{zC
} "KcA
n>@oBG)!
W3`>8v1?o
/* pv|Pm
**FileAccess.java R$;n)_H
*//文件访问(定位，写) y#}cC+;
package NetFox; [MuEoWrq(}
import java.io.*; t78k4?
I*9e]m"
h-iJlm
public class FileAccessI implements Serializable{ rG,5[/l
Kw#so; e
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P[s8JDqu
RandomAccessFile oSavedFile; +P.+_7+:
long nPos; Aw&tP[N[
*#TUGfwy
.<kqJ|SVi
public FileAccessI() throws IOException KNH1#30 K
{ THmb6^
this("",0); u2 `b'R9
} f~}H
!i=nSqW
9UvXC)R1
public FileAccessI(String sName,long nPos) throws IOException aF03a-qw<
{ cuOvN"nuNj
oSavedFile = new RandomAccessFile(sName,"rw"); %Uz(Vd#K
this.nPos = nPos; bn |zl!Pq
oSavedFile.seek(nPos); oK 6(HF'&
} f/CuE%7BR
4CGPOc
o|jIM9/
public synchronized int write(byte[] b,int nStart,int nLen) 2<M= L1\
{ Df3rV'/~
int n = -1; 6uKTGc4
try{ Jx'i2&hGN
oSavedFile.write(b,nStart,nLen); M'_9A
n = nLen; Tw +
} q^6+!&"
catch(IOException e) B]tIi^
{ 6e7{Iy
e.printStackTrace (); )7_"wD` z
} GR\5WypoJ
DY[$"8Kxcp
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return n; fu~+8CE.
} Bn>8&w/P
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*L!!]Q2c
} MDF%\Sx
g2unV[()_
=J1rlnaaEL
/* |HZTN"
**SiteInfoBean.java pmX#E
*/ 9cJH"
package NetFox; ? w^-
&y<ZE
A&>.74}p
public class SiteInfoBean { V2N_8)s9W
[Y`,qB<B
q%ow/!\;
private String sSiteURL; //Site's URL $0arz{Oh
private String sFilePath; //Saved File's Path +f[ED4E>'(
private String sFileName; //Saved File's Name < y*x]}
private int nSplitter; //Count of Splited Downloading File m*mm\wN5
|ae975
EM\'GW
public SiteInfoBean() gzeQ|m2]
{//nSplitter的缺省值为5 >MPr=W%E
//default value of nSplitter is 5 g[w,!F
this("","","",5); Z}-Vf$O~
} - M,7N}z@;
}x&N^Ky3c
Un6/e/6,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Xt#1Qs
{ H{t_xL)k.
sSiteURL= sURL; Hk|0HL
sFilePath = sPath; $-On~u0g
sFileName = sName; F]9nB3:W
this.nSplitter = nSpiltter; x"~~l
NH0qVQ@A
, lJv
} &.Zb,r$Y
`%j~|i)4
!~h}8'a?
public String getSSiteURL() /<rt1&0
{ ]^6c8sgnR
return sSiteURL; ;U_QvN|
} +S=Rn,
vVE7fq3
Kt(-@\)!
public void setSSiteURL(String value) t-LG }nv
{ u a\,->
sSiteURL = value; "]-Xmdk09
} "]\+?
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[xKd7"d/n
public String getSFilePath() x|{IwA9
{ G}9=)
return sFilePath; n#iwb0-
} 1 `KN]Nt
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SRSvot};C
public void setSFilePath(String value) 57 #6yXQ
{ sCu+Lg~f
sFilePath = value; aj}(E+
} 1@lJonlF
z.}[m,oTF
vp.ZK[/`
public String getSFileName() O-4C+?V
{ ){Ob,LEU&
return sFileName; "kc/J*u-3
} M|] "W
Ka`=WeJ|
Yf[Qtmh]I
public void setSFileName(String value) M5x U9]B
{ >fIk;6<{
sFileName = value; -@ZiS^l
} mRZ:ie
]f1{n
YX*Qd$chZ
public int getNSplitter() =r@vc
{ z'`y,8Y1l
return nSplitter; F0690v0mB[
} f#Xyoa%
sUYxT>R
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public void setNSplitter(int nCount) ~i.k$XGA
{ $2%f 8&
nSplitter = nCount; KOwOIDt
} pn*3\
} Q#EP|
nB] >!q
CNww`PX,zZ
/* Ig5L$bAM~
**Utility.java P<K){V
*/ HfLLlH<L`&
package NetFox; 4GB7A]^E
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public class Utility { tbO H#|
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IMk'#)
public Utility() C4NTh}6tT
{ Zec <m8~
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OnWx#84
} ,E.' o=Z
] 7 _`]7p
//线程睡眠 M,5"b+mX[~
public static void sleep(int nSecond) !'Q -yoHKD
{ |A8/FU2{
try{ WF\)fc#;_o
Thread.sleep(nSecond); ZR\VCVH\^
} 21(p|`X
catch(Exception e) oc^Br~ Th
{ Dk5Zh+^
e.printStackTrace (); %e@HZ"V
} |!F5.%PY
} A?G^\I~v
!yhh8p3
//日志 aAy'\T$x.
public static void log(String sMsg) K6olYG>
{ wd/< 8>2X
System.err.println(sMsg); MfmACd^3$
} &x >B
t5[[JD1V
%_Yx<wR%
public static void log(int sMsg) @JW@-9/
{ 4ikdM/
System.err.println(sMsg); "YB**Y
} ?3O9eZY@
} eznypY=
A*|cdY]HP
[le)P$#z
/* ai*f F
**TestMethod.java i>[_r,-\[
*/ V i&*&"q
package NetFox; 7$rjlVe
|X`/
+78CvjG
public class TestMethod { !pJeA)W;
*9p |HX=
S"wg2X<
public TestMethod() .Q)|vq^
{ ///xx/weblogic60b2_win.exe /cZ-tSC)o
try{ -rKO )}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^V|Oxp'7_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N4*G{g
SiteFileFetch fileFetch = new SiteFileFetch(bean); :{q"G#
fileFetch.start(); ,TRTRb;
} $#|gLVOQ
catch(Exception e){e.printStackTrace ();} <94_@3
Jxqh)l
F]mgmYD%
} #oJ5k8Wy
;}z\i
u0`%+:]0
public static void main(String[] args) =YG _z^'
{ ` gW<M
new TestMethod(); mm5$> [%U
} Uje|`<X
} ?GTU=gpQ
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