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)); 8f|+045E@
} MT@Uu
for(int i=0;i<nEndPos.length-1;i++) SkA"MhX
{ 93#wU})
nEndPos = nStartPos[i+1]; &Lgi
} MMUw+jM4
nEndPos[nEndPos.length-1] = nFileLength; #Y<b'7yJ
} JTB5#S4W
} ]dIr;x`
:J+GodW
K3t^y`z
//启动子线程 uM~j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .](s\6'
for(int i=0;i<nStartPos.length;i++) D$c4's`5
{ S-+^L|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l,3[hx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5bKn6O)K
nStartPos,nEndPos,i); Ss7XjWP.}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *,DBRJ_*7
fileSplitterFetch.start(); -n~VMLd?@
} 1{S" axSL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -vC?bumR%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }' t*BaU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Djf,#&j!3
nEndPos = " + nFileLength); OC[(Eq
// fileSplitterFetch[nPos.length-1].start(); 2]*2b{gF,
{z}OZHJN
) 4'@=q
//等待子线程结束 \D #NO
//int count = 0; g@lAk%V4
//是否结束while循环 /P|jHK|{
boolean breakWhile = false; FeFH_
"$BWP
z<mU$<
while(!bStop) [(N<E/m%B
{ Wc$1Re{z
write_nPos(); Ie?C<(8Ul
Utility.sleep(500); Z`b{r;`m8
breakWhile = true; ^T|~L<A3
<tg>1,C
%/&?t`%H
for(int i=0;i<nStartPos.length;i++) &6L{1
{ I(Yyg,1Z
if(!fileSplitterFetch.bDownOver) YvK8;<k@-?
{ ?79ABm a
breakWhile = false; Tce2]"^;
break; `D%bZ%25c
} lU.@! rGbw
} U{o0Posg
if(breakWhile) Hd)4_ uBt
break; dLm~]V3
=6TD3k6(2
L%JmdY;
//count++; ( Qw"^lE3
//if(count>4) dg1h<]T"9
// siteStop(); .Eg>)
} u#Qd`@p
Ro?aDrQ
b#^UP
System.err.println("文件下载结束！"); ;,]T|>M
} .~6p/fHX
catch(Exception e){e.printStackTrace ();} DO$jX 4
} Dw^d!%Ala
]|[oL6"
o84!$2P+w
//获得文件长度 ;p#)z/zZ
public long getFileSize() >LwZ"IEV
{ T)]5k3{
int nFileLength = -1; q8.K-"f(Q
try{ MDS;qZx=
URL url = new URL(siteInfoBean.getSSiteURL()); *#,wV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jx@3zl
httpConnection.setRequestProperty("User-Agent","NetFox"); Nq)=E[$
-lm\~VZT3
T'l >$6
int responseCode=httpConnection.getResponseCode(); {ls$#a+d
if(responseCode>=400) QOkPliX
{ -Vk+zEht
processErrorCode(responseCode); nqt;Ge M
return -2; //-2 represent access is error &V[m{.
} q7C>A`w
XU .FLNe
WLEjRx
String sHeader; uHUicZf.
%J?;@ G)r
k#%BxT
for(int i=1;;i++) [MYd15
{ <IGQBu#ZH
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h\b]>q@
//Utility.log(in.readLine()); B]q &?~
sHeader=httpConnection.getHeaderFieldKey(i); Ym5q#f)|
if(sHeader!=null) { D1.
{ T2 0dZ8{y
if(sHeader.equals("Content-Length")) ]C-hl}iq
{ ]%3o"|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g6k@E,cI_
break; YsXP$y]g-
} z{cIG8z
} ]n0kO&
else vW 0m%
break; b,8W |
} Pm6/sO
} lN)U8
catch(IOException e){e.printStackTrace ();} cejSGsW6q
catch(Exception e){e.printStackTrace ();} C XZm/^
n0kBLn
-82Rz
Utility.log(nFileLength); q3B#rje>h
[ottUS@
&)OX*y
return nFileLength; H3}{]&a
} 0x'>}5`5
?ZDXT2b~~
pm,&kE
//保存下载信息（文件指针位置） ,L^eD>|j5
private void write_nPos() b;O]@kBB
{ k`6T% [D]
try{ ? r=cLC
output = new DataOutputStream(new FileOutputStream(tmpFile)); )R+@vh#Q<$
output.writeInt(nStartPos.length); W\o(f W
for(int i=0;i<nStartPos.length;i++) xXM`f0s@+]
{ ]QM6d(zDA
// output.writeLong(nPos); )Fk%,H-1
output.writeLong(fileSplitterFetch.nStartPos); `9Zoq=/
output.writeLong(fileSplitterFetch.nEndPos); 0Np}O=>
} 9`+c<j4/B
output.close(); UwrinkoeE
} I|,^a|\
catch(IOException e){e.printStackTrace ();} 2GA6@-u\
catch(Exception e){e.printStackTrace ();} V=BF"S;-'
} ~S15tZ $
.HF+JHIUu
%p)6m2Sb
//读取保存的下载信息（文件指针位置） |j$&W;yC
private void read_nPos() IY?[0S
{ gR"'|c
try{ bWo-( qxq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); a;D{P`%n
int nCount = input.readInt(); ~sshhuF
nStartPos = new long[nCount]; /cUcfe#X
nEndPos = new long[nCount]; (X@JlAfB
for(int i=0;i<nStartPos.length;i++) 0:R}
{ 0F6^[osqtl
nStartPos = input.readLong(); h #Od tc1)
nEndPos = input.readLong(); y.26:c(
} =O1N*'e
input.close(); ngj=w;7~+
} k!b\qS~Q
catch(IOException e){e.printStackTrace ();} Mb=vIk{Bf
catch(Exception e){e.printStackTrace ();} n;)!N
} | Uf6k`
sptDzVM
;(fDR8
private void processErrorCode(int nErrorCode) >XjSVRO
{ RxY ;'NY
System.err.println("Error Code : " + nErrorCode); 3'8B rK
} *+re2O)Eh'
e3UGYwQ
x'@0]f.
//停止文件下载 tbF>"?FY/
public void siteStop() Nt9M$?\P
{ A1zM$ wDU
bStop = true; *x2+sgSf_0
for(int i=0;i<nStartPos.length;i++) |Xk'd@<
fileSplitterFetch.splitterStop(); _>%P};G{>
2i*-ET
@*e|{;X]hy
} S)of.Nq.;
} 3t5`,R1@t
//负责部分文件的抓取 u;p{&\(]
**FileSplitterFetch.java s3kHNDdC
*/ ;3OQgKI
package NetFox; YwyP+Sr\
~UX@%0%)N
(wU<Kpt?J
import java.io.*; B>*zQb2:
import java.net.*; O%;H#3kn&s
%eB0)'
y{+$B Y$_
public class FileSplitterFetch extends Thread { :2iNw>z1
,3&XV%1
X@|'#%
String sURL; //File URL 2%i_SX[
long nStartPos; //File Snippet Start Position G=/a>{
long nEndPos; //File Snippet End Position a7s+l=
int nThreadID; //Thread's ID l5QH8eNwME
boolean bDownOver = false; //Downing is over x7)j?2
boolean bStop = false; //Stop identical Yb\t0:_
FileAccessI fileAccessI = null; //File Access interface wl1i@&9
htX;"R&
DW&%"$2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException CRf!tsj@
{ F]DRT6)
this.sURL = sURL; iZ %KHqG
this.nStartPos = nStart; "{1`~pDj?
this.nEndPos = nEnd; 8TGO6oY+=
nThreadID = id; VTQ V]>|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A5cx!h
} . >[d:0
cih@:=Qy
|VxEWU/
public void run() VI7f}
{ )Kkw$aQI"d
while(nStartPos < nEndPos && !bStop) Dn~r~aR$g
{ G66sPw
"S)2<tV
<qjNX-|
try{ @q:v?AO
URL url = new URL(sURL); /8(c^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /RU'~(
httpConnection.setRequestProperty("User-Agent","NetFox"); qpzzk9ba[
String sProperty = "bytes="+nStartPos+"-"; GSo&$T;B6
httpConnection.setRequestProperty("RANGE",sProperty); l]t9*a]a
Utility.log(sProperty); jN 9|q
"&;8U.
n "?It
InputStream input = httpConnection.getInputStream(); ,(&jG^IpVJ
//logResponseHead(httpConnection); uyBmGS2
IlQNo 1
ATx6YP@7~
byte[] b = new byte[1024]; mOgsO
int nRead; &AM<H}>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7R9.g6j
{ p|fSPSz
nStartPos += fileAccessI.write(b,0,nRead); &c!d}pU}
//if(nThreadID == 1) 8axz`2`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !-%fCg(B
} I3sH8/*
gwVfiXR4
wMFo8;L
Utility.log("Thread " + nThreadID + " is over!"); n[DQ5l
bDownOver = true; &D@/_m $
//nPos = fileAccessI.write (b,0,nRead); n.9k<
} vC$Q4>m
catch(Exception e){e.printStackTrace ();} qZw4"&,j$
} 74f3a|vx/
} 0-Z sV3I&
)Dn~e#
V)x(\ls]SX
//打印回应的头信息 qkQ_#
public void logResponseHead(HttpURLConnection con) E.~;
{ a(Q4*XH4
for(int i=1;;i++) =2+';Xk\
{ 81?7u!=ic+
String header=con.getHeaderFieldKey(i); x~1.;dBF
if(header!=null) F>N3GPRl
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kg@D?VqJP
Utility.log(header+" : "+con.getHeaderField(header)); x1H?e8
else <3?T^/8
break; Ce&nMgd~
} o=/Cje
} Twqkd8[
! C}t)R]^
^Ej4^d
public void splitterStop() /P_1vQq
{ dzA5l:5
bStop = true; IX/FKSuq
} $BIQ#T>qK
W?+U%bIZ9
?t;>]Wo;
} Xxl>,QUA
)HZUCi/F]
\=n0@1Q=>
/* O<}^`4d
**FileAccess.java /WIO@c
*//文件访问(定位，写) Z)iRc$;
package NetFox; r]!<iw
import java.io.*; 7\.Ax
PT2b^PP
kk`BwRh)d;
public class FileAccessI implements Serializable{ ,$;g'z!N
m]g"]U:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 oECM1'=Bf
RandomAccessFile oSavedFile; aFkxR\x 6%
long nPos; *7L*:g
/D9FjOP
Rg:3}T`~n
public FileAccessI() throws IOException XBJ9"G5
{ R<r"jOd]
this("",0); L,@OOBD
} c k~gB
i?7%z`
{HgW9N(
public FileAccessI(String sName,long nPos) throws IOException re.%$D@
{ s3G\L<~mB
oSavedFile = new RandomAccessFile(sName,"rw"); = mnjIp
this.nPos = nPos; m~K[+P
oSavedFile.seek(nPos); HSt|Ua.c/h
} kBPFk t2
m7:E73:
Salu[)+?
public synchronized int write(byte[] b,int nStart,int nLen) [\9WqHs
{ E\M{/.4 4
int n = -1; DNgQ.lV
try{ xx}R6VKU.
oSavedFile.write(b,nStart,nLen); " mKMym2
n = nLen; x,9fOA
} eYL7G-3
catch(IOException e) uj.~/W1,!
{ Lh=~3
e.printStackTrace (); WY@x2bBi
} 47Y|1
Q37VhScs
K#"@nVWJ.m
return n; ;OYwZ
} E(G=~>P
] =Js5
//--r5Q
} {$iJYS\
(xU+Y1*g"%
{Y5h*BD>
/* _ Ko0
**SiteInfoBean.java Isq3YY
*/ 9Ao0$|@b
package NetFox; mB(*)PwZ
.js4)$W^
-;$+`<%
public class SiteInfoBean { UQ|zSalv,
7YRDQjg
=q|fe%#
private String sSiteURL; //Site's URL uTJi }4cw
private String sFilePath; //Saved File's Path D#%J||
private String sFileName; //Saved File's Name QN(f8t(
private int nSplitter; //Count of Splited Downloading File &%pB; dk
#( nheL
X$JO<@x
public SiteInfoBean() K{VF_S:
{//nSplitter的缺省值为5 BfOG e!Si
//default value of nSplitter is 5 =erA.u
this("","","",5); Vvx(7p-GQ
} $"{V],:T |
ADX}
XA])<dZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +DKrX
{ |Y<ca
sSiteURL= sURL; y? [*qnPj
sFilePath = sPath; T[))ful
sFileName = sName; 0:G@a&Lr
this.nSplitter = nSpiltter; 1at$_\{.(
Fm}O,=
81a&99k#
} | -Di/.
k;3P;@3,W
~QdwoeaD
public String getSSiteURL() hE:P'O1
{ ;hs:wLVa"
return sSiteURL; 6\86E$f=h
} 'OGOT0(
PqcuSb6
Tu_dkif'
public void setSSiteURL(String value) OxF\Hm)(
{ ZNB*Azi
sSiteURL = value; +2oZB]GPL
} 9BANCW"
^J>28Q\S
~E^EF{h
public String getSFilePath() gx[#@(
{ M;MD-|U
return sFilePath; _|8"&*T^
} *Oz5I
| 7>1)
RA[` Cp"
public void setSFilePath(String value) }VR&*UJE
{ w& RpQcV
sFilePath = value; mQ%kGqs
} 9+QLcb
NtTLvO6
=mqV&FgRo
public String getSFileName() !^axO
{ l^`!:BOtR
return sFileName; &s/aJgJhp
} ?5mVC]W?]
^Hq}9OyS9
kq%`9,XE
public void setSFileName(String value) 6}NvVolr
{ GWE`'V
sFileName = value; x6DH0*[.
} =hl-c
f| N(~
mA^>Y_:
public int getNSplitter() y6*i/3
{ =r0!-[XCa
return nSplitter; 5!nZvv
} @oRYQ|.R
,A6*EJ\w
z5'VsK:
public void setNSplitter(int nCount) WgPL4D9=
{ 3C,e>zE}
nSplitter = nCount; b}"/K$`Fd
} N=I5MQG
} i0AC.]4e"
R&xD|w8UjM
Jy|Mfl%d
/* .j&jf^a5
**Utility.java 2:DpnLU5
*/ C)C;U&Qd
package NetFox; Kv#daAU
aRG[F*BY
P`bR;2o
public class Utility { L<QDC
n@mUQ6
_)Qt,$
public Utility() bfpW^y
{ xBw"RCBz^
*Mp<4B
U'lmQrF!
} dfJ7Dhn
Ej34^*m9k
//线程睡眠 a|s=d
public static void sleep(int nSecond) [\.>BK
{ gdG: &{|x
try{ ))KsQJ"V
Thread.sleep(nSecond); 8dZH&G@;
} zIAMM
catch(Exception e) 15eHddd
{ l%w7N9
e.printStackTrace (); z:fhq:R(
} U_8I$v-~
} }bnkTC
Xr)d;@yi
//日志 pH~JPNng
public static void log(String sMsg) gRqz8UI
{ {W4t]Ff
System.err.println(sMsg); {(MG: B
} SQ1&n;M}f
sIy$}_
AMm O+E?
public static void log(int sMsg) #&5\1Qu
{ r=[}7N
System.err.println(sMsg); 9=}/t9k
} /6.b>|zF
} JWdG?[$
/nmfp&@
mn4;$1~e>H
/* ut,"[+J
**TestMethod.java L%8"d6
*/ plIx""a^h
package NetFox; 'K"*4B^3
p-6.:y
*oWzH_
public class TestMethod { =N0cz%
=~S
o{Ep/O`
public TestMethod() uJ y@
{ ///xx/weblogic60b2_win.exe vVf!XZF
try{ )/pPY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]s SoIT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2M1mdkP3
SiteFileFetch fileFetch = new SiteFileFetch(bean); ky%%H;
fileFetch.start(); .R"L$V$RU.
} X5yhS
catch(Exception e){e.printStackTrace ();} K;ML'
E4.IS=4S
n)H0;25L
} ;(,Fe/wvC
aRwBxf
'ng/A4
public static void main(String[] args) Bx)&MYY}[[
{ 4%7*tVG
new TestMethod(); 4>HGwk@+8
} sP |i'
} $g^;*>yr
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