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)); )BmK'H+l
} }HRM6fR1S
for(int i=0;i<nEndPos.length-1;i++) iW9G0Ay
{ { LZ` _1D
nEndPos = nStartPos[i+1]; %9C_p]P*
} 09HlL=0q
nEndPos[nEndPos.length-1] = nFileLength; *;5P65:u$>
} fIWOo >)D
} cA m>f[
TldqF BX
h0_od/D1r
//启动子线程 T5$db-^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2M1}`H\
for(int i=0;i<nStartPos.length;i++) GAI(=
{ q&]I
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %a$ l%8j&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~|QhWgq
nStartPos,nEndPos,i); .?|pv}V
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W"MwpV
fileSplitterFetch.start(); *.qm+#8W
} cdY|z]B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), js^+{~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MROe"Xj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2SVBuV/R
nEndPos = " + nFileLength); VI_8r5o
// fileSplitterFetch[nPos.length-1].start(); 3V2dN)\
)i|0Ubn[|
:rR)rj'
//等待子线程结束 U|yXJ.Z3
//int count = 0; I5Vp%mCY
//是否结束while循环 QmxI;l
boolean breakWhile = false; Pk)>@F<
))ArM-02
~*NG~Kn"s
while(!bStop) 3}hJ`xQ
{ ePLpGT
write_nPos(); }Y9= 3X
Utility.sleep(500); $DS|jnpV
breakWhile = true; EIdEXAC(
csK;GSp}
CmP_9M?ce
for(int i=0;i<nStartPos.length;i++) bSJ@ 5qS
{ ?E +[
if(!fileSplitterFetch.bDownOver) !DU4iq_.
{ z.Y`"B'j`
breakWhile = false; p#;I4d G
break; Q7#Yw"#G!
} b;xn0sDn#
} q#C;iK4
if(breakWhile) Bl$Hg,in-
break; [[FDt[ l4
t nvCtuaR
1RHFWK5Si
//count++; CqFk(Td9-D
//if(count>4) +%sMd]$,n
// siteStop(); ^K3Bn
} Lqa|9|!
^jYE4gHM
0#y i5U
System.err.println("文件下载结束！"); )JA9bR <
} |X47&Y
catch(Exception e){e.printStackTrace ();} }ebu@)r
} o$q})!
[x[nTIg
r}nz )=\Cj
//获得文件长度 nVyV]'-z
public long getFileSize() 1[:tiTG|C
{ _jWGwO
int nFileLength = -1; a1dkB"Zp.p
try{ F<0GX!p4u
URL url = new URL(siteInfoBean.getSSiteURL()); bDtb"V8e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )dh_eqnX
httpConnection.setRequestProperty("User-Agent","NetFox"); Q ym=L(X
5c ($~EFr
]5a,%*f+
int responseCode=httpConnection.getResponseCode(); |SX31T9rG
if(responseCode>=400) p N+1/m,
{ S;tv4JY
processErrorCode(responseCode); )0XJOm
return -2; //-2 represent access is error ~5:-;ZbZ
} Qv B%X)J
Ihy76_OZ
E}lNb
String sHeader; {Rtl<W0
HDQH7Bs
x5(B(V@b
for(int i=1;;i++) -'Oq.$Qq
{ mO^)k
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _>u0vGF-
//Utility.log(in.readLine()); ,V`[;~49
sHeader=httpConnection.getHeaderFieldKey(i); W.m2`] &
if(sHeader!=null) P$i d?
{ zlhI\jRdc
if(sHeader.equals("Content-Length")) d>hLnz1O
{ w$$vR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); snvixbN
break; MVkO >s
} _ lE d8Cb
} v]@n'!
else 7-j=he/
break; X;QhK] Z
} &Xp<%[:
} -_T@kg[0zB
catch(IOException e){e.printStackTrace ();} ?bw1zYP
catch(Exception e){e.printStackTrace ();} j-(k`w\
E-i<^&E
m!sMr^W
Utility.log(nFileLength); dPb@[k
(0!U,8zz
859ID8F
return nFileLength; dS)c~:&+
} IgNL1KRD
n]a/nv
]#P>wW
//保存下载信息（文件指针位置） <?Y.w1
private void write_nPos() 'w`3( ':=
{ s\io9'Ec
try{ 2>h.K/pC
output = new DataOutputStream(new FileOutputStream(tmpFile)); >Ni<itze$i
output.writeInt(nStartPos.length); VhX~sJ1%Gp
for(int i=0;i<nStartPos.length;i++) W8Aii'Q8C/
{ 7yFV.#K3O
// output.writeLong(nPos); *c'hmAs
output.writeLong(fileSplitterFetch.nStartPos); e!p?~70
output.writeLong(fileSplitterFetch.nEndPos); v6*8CQ+
} R^=[D#*]>
output.close(); KpSho<
} gFAtIx4
catch(IOException e){e.printStackTrace ();} (C60HbL
catch(Exception e){e.printStackTrace ();} b5Vn_;V*
} /8"9sf*
+X4/l"|
y)D7!s
//读取保存的下载信息（文件指针位置） `uLH3sr
private void read_nPos() +lED6]+%
{ d'*:2;)g^
try{ *WK0dn
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ai5|N
int nCount = input.readInt(); +9[s(E?SY
nStartPos = new long[nCount]; '.1_anE]
nEndPos = new long[nCount]; Bv(c`JE~;
for(int i=0;i<nStartPos.length;i++) =.yKl*WV{
{ )Y 9JP@}T
nStartPos = input.readLong(); mIm.+U`a2
nEndPos = input.readLong(); VtzX I2.2
} I+g[ p
input.close(); Gk2R:\/Y
} =6^phZ(
catch(IOException e){e.printStackTrace ();} 61=D&lb
catch(Exception e){e.printStackTrace ();} 1k?k{Ri
} 7<7 /NZ<I
GEQ3r'B|
HL34pmc
private void processErrorCode(int nErrorCode) cgF?[Z+x
{ N_eZz#);
System.err.println("Error Code : " + nErrorCode); 1GI/gc\
} U6 $)e.FO
\\9$1yg
5*IfI+}
//停止文件下载 N;.}g*_+}
public void siteStop() m[%*O#_
{ M73d^z
bStop = true; uIb,n5
for(int i=0;i<nStartPos.length;i++) 64w4i)?eM[
fileSplitterFetch.splitterStop(); F3pBk)>a\
- }2AXP2q
xv:VW<
} bL"!z"NA
} eh5j
//负责部分文件的抓取 %YbcI|i]<0
**FileSplitterFetch.java >4@/x{{
*/ :UDT! 5FNO
package NetFox; -`<KjS
f%JC;Y
f!n0kXVu6U
import java.io.*; l1MVC@'pvP
import java.net.*; NsY D~n
oP 4z>
v(vJ[_&%
public class FileSplitterFetch extends Thread { P}RewMJ$L
>Qg 9KGk'
hEv}g
String sURL; //File URL b w2KD7
long nStartPos; //File Snippet Start Position : ZWKrnG
long nEndPos; //File Snippet End Position <JNiW8 PG
int nThreadID; //Thread's ID GoTJm}[NP
boolean bDownOver = false; //Downing is over SB#Y^!
boolean bStop = false; //Stop identical H@%Y"iIUP
FileAccessI fileAccessI = null; //File Access interface *sbZ{{]e
jJOs`'~Q\
P/hV{@x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *dw6>G0U
{ h.ln%6:d
this.sURL = sURL; ]1k"'XG4,
this.nStartPos = nStart; MR{JMo=r
this.nEndPos = nEnd; TC$)::C1
nThreadID = id; Hz6tk9;w
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ejjL>'G/|%
} zXRq) ;s
swGp{wJ
5gZ6H/.
public void run() 8\H*Z2yF+
{ iE8
while(nStartPos < nEndPos && !bStop) THl={,Rw`
{ ?0%3~E`l:
&?)? w-$p
<RaM@E
try{ 7yM"G$
URL url = new URL(sURL); C ks;f6G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -)Zp"
httpConnection.setRequestProperty("User-Agent","NetFox"); a#L:L8T;j
String sProperty = "bytes="+nStartPos+"-"; l}jC$B`5
httpConnection.setRequestProperty("RANGE",sProperty); N9}27T+4
Utility.log(sProperty); !Yi2g-(
`EJ.L6j$'
}#Gq*^w
InputStream input = httpConnection.getInputStream(); Vhi4_~W3j]
//logResponseHead(httpConnection); BD.>aAi!
3<%ci&B
Nm.G,6<J
byte[] b = new byte[1024]; 9z9\pXFQ
int nRead; |@*3 nb8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 99G'`NO
{ _yN&+]c
nStartPos += fileAccessI.write(b,0,nRead); jo}yeGbU
//if(nThreadID == 1) yRyUOTK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mQka?_if)
} JLn)U4>z w
m*f"Y"B.1I
uK;&L?WB
Utility.log("Thread " + nThreadID + " is over!"); GnFm*L
bDownOver = true; KKcajN
//nPos = fileAccessI.write (b,0,nRead); fuQk}OW{
} ][TA7pDPV
catch(Exception e){e.printStackTrace ();} W Yo>Md 8
} 8W"Xdv{
} 5>!I6[{
#9e2+5s
rf=oH }
//打印回应的头信息 >.1d1#+b
public void logResponseHead(HttpURLConnection con) yE_T#FN
{ s/\<;g:u^
for(int i=1;;i++) 3\2^LILLO
{ i*jnC>
String header=con.getHeaderFieldKey(i); `P/87=h
if(header!=null) w/,A@fLL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dh-?_|"
Utility.log(header+" : "+con.getHeaderField(header)); 6c[Slq!KA
else x,j%3/J^2
break; "UUoT
} .$U=ngj\t
} aHkt K/
u$rSM0CJ
ys- w0H
public void splitterStop() 6ee1^>
{ Egi(z9|Pp
bStop = true; XYze*8xUb
} ^~kfo|
'>:%n
t;b1<TLn0
} TdL/tg!
L~!Lq4]V\g
,E&W{b
/* X3j|J/
**FileAccess.java z0 J:"M
*//文件访问(定位，写) *(o^w'5
package NetFox; tpQ8 m(
import java.io.*; <Q@{6
7b*9 Th*a
FPkig`(3
public class FileAccessI implements Serializable{ H)pB{W/
asL!@YE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rU_FRk
RandomAccessFile oSavedFile; g+QNIM>
long nPos; SD.c9
v M $Tn
"Xj>dB1~
public FileAccessI() throws IOException 6)1xjE#
{ qz }PTx
this("",0); _Kv;hR>
} bJB*w
=`t%p1
Wl{wY,u
public FileAccessI(String sName,long nPos) throws IOException U(\ ^!S1
{ IRbZ ;*3dO
oSavedFile = new RandomAccessFile(sName,"rw"); J\Z\q
this.nPos = nPos; 3gz4c1 s^:
oSavedFile.seek(nPos); g.x]x#BC
} ;|.IUXEgcF
eXQzCm
x<>In"QV
public synchronized int write(byte[] b,int nStart,int nLen) 2rqYm6
{ h"(HDnq
int n = -1; TN.&FDqC9
try{ fHacVjJ
oSavedFile.write(b,nStart,nLen); d~w}{LR[1
n = nLen; !po29w:S
} F2CoXe7
catch(IOException e) F}4jm,w
{ IfpFsq:
e.printStackTrace (); (\ Gs7
} d1/uI^8>
Q*caX
E{E%nXR)
return n; QW6\~l 4
} J@Qw6J
Z{ b($po
]y<<zQ_fhY
} v1~`76^
ns9a+QQ
pYaq1_<+
/* M\jTeB"Z
**SiteInfoBean.java 5E}~iC&
*/ TkV*^j5
package NetFox; Auf2JH~
Avi8&@ya
^FN(wvqb8
public class SiteInfoBean { VU 8~hF
l} UOg
|csR"DOqz
private String sSiteURL; //Site's URL f iu?mb=*
private String sFilePath; //Saved File's Path u7kw/_f
private String sFileName; //Saved File's Name M}BqSzd*
private int nSplitter; //Count of Splited Downloading File &[4lP~
QKtTy>5
BjIKs~CT
public SiteInfoBean() ay,E!G&H
{//nSplitter的缺省值为5 'hl4cHk14
//default value of nSplitter is 5 Ye) F{WqZ#
this("","","",5); L/n?1'he
} iLD:}yK
yZ]u{LJS
5rx;?yvn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #Jqa_$\.
{ )I`Ma6bX
sSiteURL= sURL; [Oy5Td7[
sFilePath = sPath; =g+Rk+jn
sFileName = sName; {@w!kl~8
this.nSplitter = nSpiltter; ~kW[d1'c
f/6,b&l,
P85@G 2
} 8RJ^e[?o(
q:/<^|
Xv'5%o^i*
public String getSSiteURL() o0'!u
{ ~E tW B
return sSiteURL; H~Fb=.h]U
} ).b,KSi
Dw6mSsC/
l4+Bs!i`
public void setSSiteURL(String value) nVt,= ?_ U
{ >MeM
sSiteURL = value; 1$#{om9
} e7^B3FOx
OW|5IEC
8A ;)5!
public String getSFilePath() V"`t*m$
{ C[xY 0<^B
return sFilePath; C>:'@o Z
} M#7w54~b?M
ecRY,MN
L d;))e
public void setSFilePath(String value) d^sm;f
{ uVn"'p-
sFilePath = value; 6*\WH%
} j aEUz5
dRD t.U!T
c?0.>^,B Q
public String getSFileName() L H8iHB
{ e(~9JP9
return sFileName; C@3`n;yZ=
} (Iz$_(
`,lry7]
zY=eeG+4s
public void setSFileName(String value) PV\aQO.mo
{ t3// U#
sFileName = value; !\6<kQg#
} ?~p]Ey}~9
<n-}z[09
fZ5zsm'N
public int getNSplitter() z?DI4O#Up
{ 0Kytg\p}
return nSplitter; h7"c_=w+
} U7do,jCoa
$"P[nNW3
e>] gCa
public void setNSplitter(int nCount) N7 FndB5%
{ ' %&gER
nSplitter = nCount; aJ/}ID
} k:QeZn(
} ?-Zl(uX
:2zga=)g
[(rT,31cW
/* 2t,N9@u=UN
**Utility.java !Soz??~o/
*/ bpx ^
package NetFox; "\k|Z
YLsOA`5X
j"F?^0aR,Q
public class Utility { ?`lD|~
.<Rw16O
>'1[Bh
public Utility() \]8F_K
{ hl]q6ZK!6
m!K`?P]:N
D 0 O^=v|
} (hJ&`Tt
'L@kZ
//线程睡眠 W=:AOBK
public static void sleep(int nSecond) ,r8#-~A6,A
{ X`6"^ xme
try{ }6_*i!68"U
Thread.sleep(nSecond); @xXVJWEU:
} YSh@+AN
catch(Exception e) `FGYc
{ Yu$QL@
e.printStackTrace (); -|GKtZ]}
} L</k+a?H!
} X- ZZLl#
Rb!y(&>v
//日志 \$4 [qG=
public static void log(String sMsg) U4.$o]58
{ J= [D'h
System.err.println(sMsg); @-ml=S7;Sz
} `/O AgV"`
N[rAb*iT
3=Q:{
public static void log(int sMsg) `Gj(>z*
{ Nq%ir8hE
System.err.println(sMsg); -VeCX]
} RR+{uSO,t
} *`q?`#1&&.
\xlG3nz
+Bf?35LP
/* _U_O0@xi
**TestMethod.java P8(hHuO
*/ )n]"~I^
package NetFox; z2>LjM) #
q;}iW:r&Q
gBky ZK
public class TestMethod { ]rv4O@||w
1ysQvz
8t3m$<7
public TestMethod() Z}TLk^_[
{ ///xx/weblogic60b2_win.exe dU#-;/}o
try{ ^)wKS]BQ..
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @c-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u&w})`+u5
SiteFileFetch fileFetch = new SiteFileFetch(bean); -@e2/6Oi
fileFetch.start(); p- a{6<h
} f4 qVUU
catch(Exception e){e.printStackTrace ();} -V:HT j
?!K6")SE
{zWR)o .=
} xbBqR_H_
5f{P% x(
hLbWqF
public static void main(String[] args) @)BO`;*$fF
{ FpiTQC7d
new TestMethod(); |mP};&b
} 3 3|t5Ia
} LQHL4jRXU
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