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)); oYHj~t
} l_3`G-`2
for(int i=0;i<nEndPos.length-1;i++) ,t}vz 7
{ -_ I_W&
nEndPos = nStartPos[i+1]; kM!kD4&
} d; [C6d
nEndPos[nEndPos.length-1] = nFileLength; (w&F/ynO:
} %/EVUN9=
} /TE_W@?^
|HU@ >
M\C"5%2Mu
//启动子线程 +_s #2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .R`5Qds*l
for(int i=0;i<nStartPos.length;i++) |yvQ[U~PQ
{ 2`.cK 3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hS_6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?=>+LqP
nStartPos,nEndPos,i); Ytgcs( /$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $r@ =*(
fileSplitterFetch.start(); R[Ll59-
} | H!28h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KjV:|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "BD~xP(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %mL-$*
nEndPos = " + nFileLength); R{RwTN<
// fileSplitterFetch[nPos.length-1].start(); R5"K]~
|b[+I?X
L9-h;] x!
//等待子线程结束 7ByTnYe~S
//int count = 0; Gb"r|(!
//是否结束while循环 ~0?mBy!-O
boolean breakWhile = false; z+ s6)Ad
k $M]3}$U
)@N2
while(!bStop) EJ@?h(O
{ hp8%.V$f
write_nPos(); >oea{u
Utility.sleep(500); l;af~ef)'
breakWhile = true; ^L0d/,ik
jQk*8
f @8mS
for(int i=0;i<nStartPos.length;i++) ,PlO8;5]
{ "-_fv5jL
if(!fileSplitterFetch.bDownOver) )X04K~6lY
{ u?>B)PW
breakWhile = false; .b\$MZ"(
break; Xm+8
} 6cpw~
} u83J@nDQ
if(breakWhile) HfcL%b%G8
break; OQ8 bI=?[x
qe#P?[
y'FS/=u>0
//count++; ~n[d4qV&
//if(count>4) t(GR)&>.2
// siteStop(); &GNxo$CG
} GGe,fb<k
ZPc@Zr`z
Wf>zDW^"R
System.err.println("文件下载结束！"); lJ+0P2@h*
} x8!ol2\`<
catch(Exception e){e.printStackTrace ();} ^BUYjq%(`
} c;{Q,"9U
yvgrIdEP
)Y]{HQd
//获得文件长度 !(qsD+
public long getFileSize() ub7zA!%
{ 6UevpDB
int nFileLength = -1; df*5,NV'-*
try{ iQ4);du
URL url = new URL(siteInfoBean.getSSiteURL()); H(2!1?N+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ".SJ~`S
httpConnection.setRequestProperty("User-Agent","NetFox"); Wqc)Fv70m
_nD$b={g
FvN<<&B
int responseCode=httpConnection.getResponseCode(); {D!6%`HKV+
if(responseCode>=400) Op"M.]#
{ o8zy^zN$6
processErrorCode(responseCode); y'(Ne=y
return -2; //-2 represent access is error M(RZ/x
} DjI3?NN
\I["2C]3M
!1n8vzs"c
String sHeader; fR)m%m
]BtbWKJBqe
6}4'E
for(int i=1;;i++) >RPd$('T
{ ONx(]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); BJgW,huLy
//Utility.log(in.readLine()); 53c0 E
sHeader=httpConnection.getHeaderFieldKey(i); ?|WoIV.
if(sHeader!=null) !iH-#B-
{ bKj%s@x
if(sHeader.equals("Content-Length")) PlF87j (
{ 8i|w(5m;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |l&vkRrN
break; RG3l.jL
} 3<k`+,'
} u\LiSGePN
else fLDg~;3
break; TlI<1/fP}
} fBgEnz/
} !_+8A/
catch(IOException e){e.printStackTrace ();} RletL)
catch(Exception e){e.printStackTrace ();} IP``O!WP
F6o_b4l
uHH/rMV
Utility.log(nFileLength); %7#-%{
CNQC^d\ h
TT50(_8
return nFileLength; *.~6S3}
} X/z6"*(|/
s7g(3<(
/CuXa%Ci^
//保存下载信息（文件指针位置） T<JwD[(
private void write_nPos() SrFS#
{ ?+g`HTY u
try{ S!Omy:=;i
output = new DataOutputStream(new FileOutputStream(tmpFile)); nl(WJKq'
output.writeInt(nStartPos.length); K+Z+wA?
for(int i=0;i<nStartPos.length;i++) )uK{uYQl
{ CM<]ZG7
// output.writeLong(nPos); # altx=6'
output.writeLong(fileSplitterFetch.nStartPos); >H(i^z/c
output.writeLong(fileSplitterFetch.nEndPos); nB%;S
} D?C)BcN
output.close(); aO@7O*
} %FS$zOsgGK
catch(IOException e){e.printStackTrace ();} }8@M@
catch(Exception e){e.printStackTrace ();} 28/ ADZ
} mNb ?*3\
V$"ujRp
q(zJ%Gv)
//读取保存的下载信息（文件指针位置） %VzKqh
private void read_nPos() fLSXPvm
{ @%tRhG
try{ ~XyW&@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fwrJ!j
int nCount = input.readInt(); "t({D
nStartPos = new long[nCount]; 5DXR8mLoaJ
nEndPos = new long[nCount]; ~7$&WzD
for(int i=0;i<nStartPos.length;i++) Nc:({@I
{ ({-GOw46
nStartPos = input.readLong(); n6*En7IVh
nEndPos = input.readLong(); !L;\cl
} P6 ;'Sza
input.close(); Di@GY!
} N[<H7_/3
catch(IOException e){e.printStackTrace ();} r'dr9"-{
catch(Exception e){e.printStackTrace ();} "p/j; 6H
} /,MJq#@K
B|C/ Rk6?
+$$$
private void processErrorCode(int nErrorCode) #'-Sh7ycW
{ UK$ms~H
System.err.println("Error Code : " + nErrorCode); v1|Bf8
} J[A14z]#`
eVt$7d?Jw
aWwPvd3
//停止文件下载 _bzqd" 31I
public void siteStop() a@@M+9Q
{ p}|.ZkyN
bStop = true; @WQK>-=(3
for(int i=0;i<nStartPos.length;i++) G [:N0{v5
fileSplitterFetch.splitterStop(); |y h\
'zEI;v
:U d
} rwniOQe
} DNR~_3Aq
//负责部分文件的抓取 )mJf|W!Z#
**FileSplitterFetch.java `C_jP|[e
*/ /erN;Oo%<
package NetFox; Dy]I8_
>6~k9>nDb<
RrhT'':[
import java.io.*; 4\pWB90V
import java.net.*; j ,)P9V
DbZ0e5
7R3fqU.Rq
public class FileSplitterFetch extends Thread { %*o8L6Hn
'qArf
=\,uy8HX
String sURL; //File URL zP:cE
long nStartPos; //File Snippet Start Position FYb34LY
long nEndPos; //File Snippet End Position W(25TbQ
int nThreadID; //Thread's ID +&X%<S W
boolean bDownOver = false; //Downing is over -w;(cE
boolean bStop = false; //Stop identical v}sY|p"
FileAccessI fileAccessI = null; //File Access interface Og2vGzD
p1D[YeF4
cO\-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t ?h kL
{ $s4Wkq
this.sURL = sURL; \eGKkSy
this.nStartPos = nStart; @)>D))+
this.nEndPos = nEnd; uK("<u|
nThreadID = id; mv atUe
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9Ew7A(BG_3
} B-*E:O0y
SVa6V}"Iv
FZ|CqD"#
public void run() !@I}mQ ~
{ Uu"0rUzt
while(nStartPos < nEndPos && !bStop) QN>7~=`
{ rVtw-[p
6CC&Z>
-ZW3
try{ .c^ ggy%
URL url = new URL(sURL); l;"Ab?P\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *9 Q^5;y
httpConnection.setRequestProperty("User-Agent","NetFox"); [EY`am8[
String sProperty = "bytes="+nStartPos+"-"; oyk>vIZ
httpConnection.setRequestProperty("RANGE",sProperty); <e)o1+[w
Utility.log(sProperty); a`E*\O'd
_Cy:]2o
v)f7};"z
InputStream input = httpConnection.getInputStream(); `_5GG3@Ff
//logResponseHead(httpConnection); cBYfXI0`
Eq^uKi
v8/6wy?
byte[] b = new byte[1024]; `W `0Fwu9
int nRead; a=xT(G0Re
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pilh@#_h
{ EPX8Wwf
nStartPos += fileAccessI.write(b,0,nRead); H@l}[hkP
//if(nThreadID == 1) F_ 7H!F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8ga_pNe
} \OC6M` /
pO~c<d}b
.>Z,uT^A
Utility.log("Thread " + nThreadID + " is over!"); F?u^"}%Fc
bDownOver = true; y^Vw`-e
//nPos = fileAccessI.write (b,0,nRead); 1ndJ+H0H
} w%c
catch(Exception e){e.printStackTrace ();} |xr\H8:(!
} 1%J.WH6eQ
} `Zz uo16
;pJ2V2 g8
ogeL[7
//打印回应的头信息 h?UVDzI!O
public void logResponseHead(HttpURLConnection con) a :HNg
{ ;`v% sx#
for(int i=1;;i++) }:z5t,u6
{ h:/1X' 3d
String header=con.getHeaderFieldKey(i); i2Jq|9,g
if(header!=null) [m'CR 4(|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2.Yi(r
Utility.log(header+" : "+con.getHeaderField(header)); HFo-4"
else +VU4s$w6
break; c 5`US
} 68R1AqU_
} ~V)?>)T
~S; Z\
%*z-PT22
public void splitterStop() mzD^Y<LTd
{ uXQ >WI@eF
bStop = true; "DSPPE&[c
} 5V-jMB
$R^AEa7
Q;h3v1GC\P
} |@j_2Q,
+&ZX$
.~=HgOJ
/* ,smF^l
**FileAccess.java Psa@@'w
*//文件访问(定位，写) znZ7*S >6\
package NetFox; ~# 7wdP
import java.io.*; _qWC4NMF(
9 1P4:6
80ZnM%/}
public class FileAccessI implements Serializable{ rUwE?Ekn/
ivrXwZ7jT
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %*)2s,8
RandomAccessFile oSavedFile; 8 #oR/Nt
long nPos; #Ogt(5Sd
|$hgT K[L
I__4I{nI
public FileAccessI() throws IOException ])y{BlZ
{ zW4O4b$T
this("",0); ]UNZd/hIL
} Fa3gJ[ZAqf
S|R|]J|
3@5p"X
public FileAccessI(String sName,long nPos) throws IOException j%& IL0
{ V`fL%du,3
oSavedFile = new RandomAccessFile(sName,"rw"); &K:' #[3V
this.nPos = nPos; #iis/6"
oSavedFile.seek(nPos); tLX,+P2|
} 2HOe__Ns
M?o{STt
FMu!z
public synchronized int write(byte[] b,int nStart,int nLen) ;Gm>O7"|@
{ r(uP!n1+
int n = -1; (;6s)z
try{ :%_q[}e
oSavedFile.write(b,nStart,nLen); HdQj?f3
n = nLen; Li`hdrO'ii
} ]TK=>;&
catch(IOException e) 3n(*E_n
{ t]m!ee8*X<
e.printStackTrace (); 02 f9 wV
} TGWdyIk
(:$9%,x
EI`vVI
return n; 3-Y=EH_0
} d><fu]'
mf4z?G@6
` %' z
} Ao`_",E
b>q6:=((
6S*zzJ.0K
/* zW'/2W.
**SiteInfoBean.java 4DML
*/ z Bf;fi
package NetFox; ^eTZn[qH>w
kMe@+ysL
QTh0SL
public class SiteInfoBean { ;?im(9h"v!
aR(E7mXQ
&d 3HB=x
private String sSiteURL; //Site's URL &|z544
private String sFilePath; //Saved File's Path ag]*DsBt
private String sFileName; //Saved File's Name \8_V(lU
private int nSplitter; //Count of Splited Downloading File ABWb>EZ8
+rQg7a}
URw!7bTz
public SiteInfoBean() Ve:&'~F2 s
{//nSplitter的缺省值为5 |(%AM*n
//default value of nSplitter is 5 Z% Z"VoxH
this("","","",5); ggCr-
} T <A
^_w*XV
@aB9%An1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }=pOiILvD
{ QV)}3pW
sSiteURL= sURL; Gm@iV,F%R
sFilePath = sPath; T{ nQjYb?
sFileName = sName; wG:$6
this.nSplitter = nSpiltter; UT-ewXh
pYGYy'%A'
FH -p!4+]
} n8FT<pUq
8dV=1O$/
GEi MmH?
public String getSSiteURL() vU9~[I`^p
{ }wkaQQh
return sSiteURL; -,@bA @&
} =|#w.(3y
-y<x!61
rIp'vy S\p
public void setSSiteURL(String value) gN\*Y
{ s;>VeD)*)
sSiteURL = value; :xN8R^(
} ;Bnr='[
x?>!UqgkY
P7Z<0Dt\}
public String getSFilePath() T:)% P6/
{ ._K$0U!
return sFilePath; hwZ6.
} 5^o3y.J?P
.r6YrB@['
vu>YH)N_h
public void setSFilePath(String value) (JvQ-H
{ Z_jn27AC
sFilePath = value; .='3bQ(UZ4
} `&G}
johmJLC
L+(C5L93}
public String getSFileName() xrX?ZJ
{ Dwk$CJb3-
return sFileName; /\TlO.B=
} rN'.&;Y5
7zi"caY
-Cml0}.O
public void setSFileName(String value) V[To,f
{ ylT6h_z1[Y
sFileName = value; mj,qQ=n;p
} `L+~&M
vsw7|
lbG}noqb
public int getNSplitter() j& <tdORT
{ d{iL?>'?^
return nSplitter; +H?<}N*T
} QQSH +
&s2#1
0K`ZX&K?W
public void setNSplitter(int nCount) B>ge, }{
{ '[n)N@h
nSplitter = nCount; }^IwQm*i
} f>?^uSpWH
} L F8Pb;I
.O;!W<Ef$
*EX$v4BX
/* 1Q0%7zRirI
**Utility.java ;7wwY$PBH
*/ ;!^ +N
package NetFox; ./';P<)
(v|ixa
p"g1V7B
public class Utility { D8q3TyCj%
Rd .U;>
J.*[gt%O|
public Utility() mQmBf|Rl
{ ntDRlX
%GNUnr$
5#yJK>a7
} HDa~7wE
l@~1CMyN
//线程睡眠 r94j+$7
public static void sleep(int nSecond) Y1m}@k,+M
{ >a?OXqYP
try{ D$Kz9GVZq
Thread.sleep(nSecond); y*y`t6D
} e~tr^$/(
catch(Exception e) iLjuE)6-$
{ d3\OHkM0^
e.printStackTrace (); 9k(*?!\;
} rSM$E
} kQqBHA
U)SM),bE[
//日志 v; je<DT
public static void log(String sMsg) y21)~
{ L7i}Ga!8
System.err.println(sMsg); 16a_GwfM
} E\ K
E`A<]dAoK
L"Qh_+
public static void log(int sMsg) i5ajM,i/K
{ R>/QARX
System.err.println(sMsg); "$`wk
} D2>hMc
} 4.,KEt'H
<K=@-4/Bp
Eqz4{\
/* ?|%\<h@;
**TestMethod.java TBoM{s=.
*/ <`oCz Q1
package NetFox; ORV}j,Ym
V%X:1 8j
c^i"}2+
public class TestMethod { 3bT6W,J4T
[[";1l
OqEg{o5 a&
public TestMethod() {^PO3I
{ ///xx/weblogic60b2_win.exe 2LhfXBWf
try{ pDLu+}@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5`1(}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); */0vJz%<.M
SiteFileFetch fileFetch = new SiteFileFetch(bean); c9Y2eetO
fileFetch.start(); mB{&7Rb0
} *"|VNnB
catch(Exception e){e.printStackTrace ();} Q0 uP8I}n
5Z4(J?n
icKg7-$N
} ]7XkijNb
lpM>}0v
w^:V."}-$
public static void main(String[] args) oTplxF1
{ ``2QOu 1
new TestMethod(); _IQU<Za
} fPh}l
} h"RP>fZt
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