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)); `~;`q
} NO'37d
for(int i=0;i<nEndPos.length-1;i++) QXLHQ_V
{ Uz$.sa
nEndPos = nStartPos[i+1]; 5u=$m^@{
} /_{B_2i/>
nEndPos[nEndPos.length-1] = nFileLength; 7%)KB4(\_
} BH3%dh:9
} u!@(u!Qz
yq<mE(hS?
J)n^b
//启动子线程 Ef2i#BoZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sn-P&"q
for(int i=0;i<nStartPos.length;i++) ms/!8X$Mz
{ K|V<e[X[V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +DwE~l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tcD DX'S
nStartPos,nEndPos,i); 6i7+.#s
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JZ>E<U9&
fileSplitterFetch.start(); J2avt
} W<tw],M-#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;w(tXcXZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DU|>zO%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", a,`f`;\7N%
nEndPos = " + nFileLength); W:S?_JM
// fileSplitterFetch[nPos.length-1].start(); ]X\p\n'@j
'MK"*W8QRM
7M,(!*b
//等待子线程结束 -POsbb>
//int count = 0; eFXQ~~gOj
//是否结束while循环 PHU$<>
boolean breakWhile = false; 0qp Pz|h
^+k~{F,)
#Mm1yXNu
while(!bStop) c5- 56Q
{ {NTMvJLm
write_nPos(); DNu-Ce%
Utility.sleep(500); HD!2|b~@
breakWhile = true; /{%p%Q[X
A(}D76o_
.9VhDrCK
for(int i=0;i<nStartPos.length;i++) k^Qd%;bdF
{ '4e, e|r
if(!fileSplitterFetch.bDownOver) Boj#r ,x
{ wY xk[)&Y
breakWhile = false; *&O4b3R
break; <swfYT!N
} @O9wit.
} Qr9@e Q1Pp
if(breakWhile) hq*"S-N
break; uWDWf5@
4`zK`bRcK#
}CGA)yK~3
//count++; PfjD!=yS=h
//if(count>4) 8{DW$ZtR
// siteStop(); f~P~%
} %pj T?G7
zJH:`~GxE
tb/`*Yl@
System.err.println("文件下载结束！"); dj2w_:&W
} (;cKv
catch(Exception e){e.printStackTrace ();} j^6,V\;l
} BK)3b6L=%
AOv>O52F/Q
]47!Zo,
//获得文件长度 6(8zt"E
public long getFileSize() ZO8r8 [
{ ["0DXm%t
int nFileLength = -1; iT=h}>
try{ bR*} s/
URL url = new URL(siteInfoBean.getSSiteURL()); RXw }Tb/D8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &|I{ju_
httpConnection.setRequestProperty("User-Agent","NetFox"); `dJ?j[P,p
S5/p3;O\c
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int responseCode=httpConnection.getResponseCode(); 5gKXe4}\/|
if(responseCode>=400) zT+ "Z(oz,
{ <[A;i
processErrorCode(responseCode); uFnq3m^u
return -2; //-2 represent access is error ]FEsN6
} [vn"r^P
>=K~*$&>
(Qd@Q,@(s
String sHeader; zn#lFPj12
-'rb+<v
Wxzh'c#\8
for(int i=1;;i++) v-&@c
{ F@<^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "Tnmn@
//Utility.log(in.readLine()); 3U4h>T@s|
sHeader=httpConnection.getHeaderFieldKey(i); 'k9Qd:a}
if(sHeader!=null) Z)!#+m83>-
{ %TYe]^/'y
if(sHeader.equals("Content-Length")) Rja>N)MzBf
{ '#u=wyp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0)Q*u
break; qk=OodEMK
} Yv"-_
} /E^j}H{
else 1EQLsg`d^
break; ZsN3 MbY
} :RDQP
} d;v<rw
catch(IOException e){e.printStackTrace ();} i?n#ge
catch(Exception e){e.printStackTrace ();} <(_${zR
C *]XQ1F4
GzjC;+W
Utility.log(nFileLength); jwO7r0?\`G
#B@*-
JlE b
return nFileLength; :LLz$[c8
} qJK-HF:#
N**"u"CX
UQnv#a>
//保存下载信息（文件指针位置） ^~W s4[Guo
private void write_nPos() d(F4-kBd
{ tUhr gc
try{ p!7(ayu
output = new DataOutputStream(new FileOutputStream(tmpFile)); S4D~`"4$/
output.writeInt(nStartPos.length); 8X)1bNGqhe
for(int i=0;i<nStartPos.length;i++) ,U=7#Cf!
{ 1?{w~cF}
// output.writeLong(nPos); O#`y;%
output.writeLong(fileSplitterFetch.nStartPos); jBU!xCO
output.writeLong(fileSplitterFetch.nEndPos); 1i}p?sU
} pykRi#[UrX
output.close(); V"5LNtf
} `o6T)49
catch(IOException e){e.printStackTrace ();} &24>9
catch(Exception e){e.printStackTrace ();} xbsX-F
} 15ImwQ
(``|5;T\
O6]X\Cwj%
//读取保存的下载信息（文件指针位置） dF'oZQz
private void read_nPos() ~`<_xIvrq
{ 23'Ac,{
try{ }u.1$Y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A?H.EZ
int nCount = input.readInt(); aj}#~v1
nStartPos = new long[nCount]; hD,@>ky
nEndPos = new long[nCount]; [-2Tj)P C
for(int i=0;i<nStartPos.length;i++) $o^N_`l
{ k@Bn}r
nStartPos = input.readLong(); #R#|hw
nEndPos = input.readLong(); /OeOL3Y
} tx]!|x" F
input.close(); M[6WcH0/T
} \= Wrh3
catch(IOException e){e.printStackTrace ();} J-W8wCq`
catch(Exception e){e.printStackTrace ();} tNYCyw{K
} dwz{Yw(
crU]P $a
YiC_,8A~
private void processErrorCode(int nErrorCode) a3^({;k!0
{ g>H\"cUv
System.err.println("Error Code : " + nErrorCode); X_#,5t=7
} j]
U}SN#[*
_Sult;y"u
//停止文件下载 ^i6`w_/
public void siteStop() XT\Q"=FD
{ \"l/D?+Q
bStop = true; ;w^{PZBg
for(int i=0;i<nStartPos.length;i++) Z'_EX7r
fileSplitterFetch.splitterStop(); P|;=dX#-
(z^987G
!N\i9w}
} ^\FOMGai
} &u0on)E
//负责部分文件的抓取 E\XD~
**FileSplitterFetch.java |1UJKJwX
*/ 92g&,Wb
package NetFox; kXW$[R
W)2ZeH*
T4x[ \v5d
import java.io.*; ;{ESo?$*
import java.net.*; -](3iPy}
NXdT"O=P
O*PJr[Zou
public class FileSplitterFetch extends Thread { F/U38[
GKf%dKL
HKYJgx
String sURL; //File URL ,dSP%?vV
long nStartPos; //File Snippet Start Position ="s>lI-1a
long nEndPos; //File Snippet End Position YHI@Cj
int nThreadID; //Thread's ID kcZz WG|n
boolean bDownOver = false; //Downing is over 5 DvD
boolean bStop = false; //Stop identical FWuk@t[<O
FileAccessI fileAccessI = null; //File Access interface i`EG80\[Z
qh/}/Sl;
EALgBv>#ZL
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d1n*wVl
{ kqp*o+Oz',
this.sURL = sURL; t"FB}%G
this.nStartPos = nStart; 6F08$,%Y
this.nEndPos = nEnd; bj U]]
nThreadID = id; j(];b+>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BYXMbx
} ;09U*S$eK
7A4_b8
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public void run() Un{9reX5
{ k{.`=j
while(nStartPos < nEndPos && !bStop) "oo j;
{ [:bYd}J
lwp(Pq
xQ@gh ( (
try{ p$zj2W+sN
URL url = new URL(sURL); ys Td'J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <wO8=bem
httpConnection.setRequestProperty("User-Agent","NetFox"); LV$`bZ
String sProperty = "bytes="+nStartPos+"-"; 4%,E;fB?=
httpConnection.setRequestProperty("RANGE",sProperty); W5zlU2
Utility.log(sProperty); 7Un5Y[FZo
E:S (v
+G[N lb
InputStream input = httpConnection.getInputStream(); -+Ab[
//logResponseHead(httpConnection); fv?vfI+m
Sz'JOBp
8ZvozQE
byte[] b = new byte[1024]; H\@@iK=
int nRead; i9quP"<9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^{w]r5d
{ 6qkMB|@Ix
nStartPos += fileAccessI.write(b,0,nRead); 2]/[
//if(nThreadID == 1) =#sr4T
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }='1<~0
} !(-S?*64l
6A*k
$ru()/pI)z
Utility.log("Thread " + nThreadID + " is over!"); B kWoK/f4
bDownOver = true; ;&MI M`&$
//nPos = fileAccessI.write (b,0,nRead); 9|9Hk1
} D+xHTQNTL
catch(Exception e){e.printStackTrace ();} sQ>L3F;A`
} Gtpl5gQH
} Kitx%P`i
]Y@B= 5e/
2fv`O
//打印回应的头信息 % C.I2J`_
public void logResponseHead(HttpURLConnection con) !e0~|8
{ ";$rcg"%X
for(int i=1;;i++) `UDB9Ca
{ UgjY
String header=con.getHeaderFieldKey(i); t>izcO
if(header!=null) j`pX2S
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cop \o4ia
Utility.log(header+" : "+con.getHeaderField(header)); t?<pyw $
else >V1v.JH
break; ;R8pVj!1f
} fNTe_akp
} )S2GPn7
zxffjz,Fe:
"[t (u/e
public void splitterStop() ~v+A6N:qC
{ !w}cKm
bStop = true; ^B`*4
} m"y_@Jk
896oz>
xvx+a0 A
} 27q=~R}
c.;}e:)s
9pJk.Np0
/* J;AwC>N
**FileAccess.java ym~
*//文件访问(定位，写) 9yt)9f
package NetFox; ?ot7_vl
import java.io.*; "ke>O'
VA^yv1We
r{pbUk
public class FileAccessI implements Serializable{ %SHgXd#X
y(w&6:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _)U[c;^6
RandomAccessFile oSavedFile; WY)*3?
long nPos; ^vA"3Ixb!
pni*#W*n
S7Tc9"oqV
public FileAccessI() throws IOException q{:]D(
{ uKL4cr@
this("",0); j{?ogFfi
} MaS"V`NI
,VdNP
oZCjci-
public FileAccessI(String sName,long nPos) throws IOException a\@k5?
{ cFF'ygJ/
oSavedFile = new RandomAccessFile(sName,"rw"); {/E_l
this.nPos = nPos; Qf:#{~/
oSavedFile.seek(nPos); }S_#*N)i
} ^0fe:ac;
N" =$S|Gs
{)L*\r
public synchronized int write(byte[] b,int nStart,int nLen) r-aCa/4y!
{ ~(~ y=M
int n = -1; >o_cf*nx
try{ zHu w[
oSavedFile.write(b,nStart,nLen); dum(T
n = nLen; n=8DC&
} .s8u?1b
catch(IOException e) Rxfhk,I
{ E# UAC2Q
e.printStackTrace (); (S)jV0
} ]qPrXuS/
fUV;3du
4Y `=`{Q
return n; W#sCvI@
} =`W#R
cf{rK`Ff^
iR39lOr
} t8_i[Hw6D
dZIruZ)x
5`QN<4?%
/* ,E3Ze*(U
**SiteInfoBean.java (\o &Gl
*/ `\Ye:$q
package NetFox; [+.P'6/[$R
H5X.CcI&}
mVVL[z2+
public class SiteInfoBean { -?Kd[Ma
^P~NE#p5
2}xvM"k=k
private String sSiteURL; //Site's URL q2}6lf,J K
private String sFilePath; //Saved File's Path ToE^%J4
private String sFileName; //Saved File's Name s.j6" Q[W
private int nSplitter; //Count of Splited Downloading File }F=lG-x
MNWuw;:v
kB3@;z:
public SiteInfoBean() gl>%ADOB@
{//nSplitter的缺省值为5 t^5xq8w8
//default value of nSplitter is 5 8;GuJP\
this("","","",5); E*G{V j
} Q)L6+gW^
qfS ]vc_N
)FSa]1t;x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O;H|nW}
{ n1r'Y;G
sSiteURL= sURL; eccJt
sFilePath = sPath; ;!Q}g19C
sFileName = sName; 6H'W]T&
this.nSplitter = nSpiltter; a*bAf'=
\wM8I-f!
!v68`l15
} JSu+/rI1
mr<camL5
} 3JOC!;;
public String getSSiteURL() ]aI
{ Q1^kU0M}
return sSiteURL; kH">(f
} cTu"Tu\Qw
9?.
r31)Ed$
public void setSSiteURL(String value) 5"mH6%d :8
{ kmur={IR
sSiteURL = value; eYD-8*
} BVe c
Cu`ty] -'
&[qJ=HMm I
public String getSFilePath() {2T;^+KE
{ !.@F,wZvY
return sFilePath; d$#DXLA\P
} ihBIE
9six]T
&b9bb{y_$K
public void setSFilePath(String value) 1dl(`=^X
{ y1_z(L;I
sFilePath = value; :7[4wQDt4
} 0}qnq"
HC(7,3
RI&V:1
public String getSFileName() BI:O?!:9)
{ qt`HP3J&
return sFileName; ~=k?ea/>
} Yx':~
NT;cTa=;
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public void setSFileName(String value) 6~tj"34_
{ 4gh` >
sFileName = value; $*c!9Etl4
} ufvjW]
DT[WO_=
4`]
public int getNSplitter() 6oy[0hj
{ %6cbHH
return nSplitter; \W+Hzf] W#
} 3_N1y
>gf,8flgj
fir#5,*q|
public void setNSplitter(int nCount) Q=h37]U+
{ tKYg
nSplitter = nCount; {ug*
} vpz l{
} V@pUU~6R
r:--DKt
rp,Us#>6
/* ",P?jgs^g5
**Utility.java GxS!Lk
*/ 9{CajtN
package NetFox; Rh%C$d(
$%.,=~W7
?eDZ-u9)
public class Utility { ih(Al<IS
7}puj%JS /
o,[Em<
public Utility() hr`,s!0Y
{ V<Co!2S
"1%\Fil
E'^ny4gL
} 0y3C />a
He1~27+99
//线程睡眠 }gKY_e3
public static void sleep(int nSecond) =kjD ]+l
{ lu;gmWz
try{ @`XbM7D 5
Thread.sleep(nSecond); gf70 O>E
} O:Wd ,3_
catch(Exception e) SXx4^X
{ vDCbD#.6
e.printStackTrace (); DWupLJpk;c
} uLr-!T
} J~)JsAXAI
BFZ\\rN`
//日志 t|C?=:_
public static void log(String sMsg) 5?*Iaw
{ TGuCIc0B{
System.err.println(sMsg); t(1gJZs>kX
} T'a&
c3(0BSv
s:ojlmPb
public static void log(int sMsg) YM#J_sy@J.
{ ]l^"A~va
System.err.println(sMsg); zqxN/H]z
} lcXo>
} `l
dQ Lo,S8(
Kl]l[!c7$
/* \qJ cs'D
**TestMethod.java Y8for'
*/ qRXHaQi@9
package NetFox; F]cc?r312
ro8C^d]
(@Eb+8Zd
public class TestMethod { 6kO+E5;X
rges`&0
%'eaW
public TestMethod() jvhD_L/
{ ///xx/weblogic60b2_win.exe Tsocc5gWZ*
try{ h9QQ8}g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :=\`P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f{U,kCv
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?f*>=;7=
fileFetch.start(); j-v/;7s/B
} Sg1,9[pb
catch(Exception e){e.printStackTrace ();} 4%7Oaf>9
8#IEE|1
m5l&
} 3v3`d+;&
S2?)Sb`
0aGAF ]
public static void main(String[] args) x$KQ*P~q
{ L#fSP
new TestMethod(); J]|S0JC`
} 3iw.yR
} g_)i)V
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