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)); [H5TtsQ[
} TN}YRXtW+
for(int i=0;i<nEndPos.length-1;i++) 4]jN@@
{ [6Y6{.%~
nEndPos = nStartPos[i+1]; f?T6Ne'
} [$_d|Z
nEndPos[nEndPos.length-1] = nFileLength; D;.O#bS
} mw9;LNi\D
} z5PFppSQ
J&w%lYiu5
K^bzZa+a
//启动子线程 :1"{0gm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h% BA,C
for(int i=0;i<nStartPos.length;i++) ;hi+.ng_
{ jA R@?X
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hc}dS$=C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vh3Xd\N
nStartPos,nEndPos,i); 7q*L-Xe]k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O;c;>x_dA
fileSplitterFetch.start(); /Fej)WQp
} dg/OjiD[P
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'NF_!D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {7&(2Z]z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =D.M}xqo
nEndPos = " + nFileLength); ,@ A1eX}
// fileSplitterFetch[nPos.length-1].start(); lj$\2B
%m]9";
L@Fw;G|%'
//等待子线程结束 ^OKCvdS
//int count = 0; xg %EQ
//是否结束while循环 [{e[3b*M|
boolean breakWhile = false; !0:uM)_k
PLR[nB7K
J >Zd0Dn
while(!bStop) i8pM,Ppi~
{ a9PSg/p
write_nPos(); _?&$@c
Utility.sleep(500); {s!DRc]ln
breakWhile = true; ZKTOif}
UA$ XjP
n5dFp%k
for(int i=0;i<nStartPos.length;i++) O,6Upk
{ Q':xi;?Kt
if(!fileSplitterFetch.bDownOver) 2C^/;z
{ laN:H mR8
breakWhile = false; 7UvfXzDNC
break; %7 h_D
} <CIJg*
} ko\VDyt,
if(breakWhile) F2!C^r,~L
break; !K^.r_0H.
v 0mc1g+9
h}fz`ti U
//count++; d)F~)}TFM
//if(count>4) K.c6n,'
// siteStop(); 8<ZxE(v
} =!m5'$Uz>
57IAH$n8o
^c3~CD5H 3
System.err.println("文件下载结束！"); 3RG*:9
} :5hKE(3Q
catch(Exception e){e.printStackTrace ();} ocBfs^ aW
} MIvAugUOl
,R/HT@
4d3]L` f
//获得文件长度 nsFOtOdd
public long getFileSize() L A-H
{ |f1 S&b.
int nFileLength = -1; {_QXx
try{ Gqq%q!k&1
URL url = new URL(siteInfoBean.getSSiteURL()); <a7y]Py
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \xG>>A%
httpConnection.setRequestProperty("User-Agent","NetFox"); 8 hx4N
J'9hzag
]TQ2PVN2
int responseCode=httpConnection.getResponseCode(); v'uWmL7C
if(responseCode>=400) Y`jvza%
{ $j*%}x~[
processErrorCode(responseCode); %Cbqi.iuQ
return -2; //-2 represent access is error OW1i{
} I\E`xkbBu
,K=\Y9l3
(hej 3;W
String sHeader; .&dW?HS
P3X;&iT
D@ut -J(.
for(int i=1;;i++) b,"gBg
{ KM$Lu2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `>&V_^y+
//Utility.log(in.readLine()); /.r|ron:e
sHeader=httpConnection.getHeaderFieldKey(i); p>Dv&fX
if(sHeader!=null) v3!oY t:l
{ :N$^x /{
if(sHeader.equals("Content-Length")) Z18T<e
{ =.`(KXT
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .lnyn|MVb
break; S]&f+g}&w
} SyFw
} yJ*`OU#
else 7(cRm$)L
break; 1!_$HA
} [.Vy
} {`,dWjy{%
catch(IOException e){e.printStackTrace ();} _/Ky;p.
catch(Exception e){e.printStackTrace ();} ,:POo^!/fT
uFQ;}k;}
vYQ0e:P
Utility.log(nFileLength); 4FURm@C6
Nn<TPT[,
e;L++D
return nFileLength; h>\T1PM
} J%ng8v5ex
JDPn
n{sF'n</
//保存下载信息（文件指针位置） SQ%B"1&$D
private void write_nPos() ;NNYJqWd^]
{ j"6r]nc&
try{ o %GVg
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8,iBG! RF
output.writeInt(nStartPos.length); &Omo\Oq&W>
for(int i=0;i<nStartPos.length;i++) lz2B,#
{ 02B *cz_K
// output.writeLong(nPos); D2N| A
output.writeLong(fileSplitterFetch.nStartPos); vN#?>aL
output.writeLong(fileSplitterFetch.nEndPos); 0#1hkJ"
} 'J\nvNm
output.close(); Fy:CG6@X
} ]@E_Hx{S
catch(IOException e){e.printStackTrace ();} mQEE?/xX;
catch(Exception e){e.printStackTrace ();} {*utke]}*
} n N.6?a
&V/n!|q<H
vbEAd)*S
//读取保存的下载信息（文件指针位置） >h:rYEsh8V
private void read_nPos() LsaE-l
{ \Ps}1)wT
try{ cV]c/*zA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kaM=Fk=t
int nCount = input.readInt(); zq]I"0Bi.
nStartPos = new long[nCount]; 5cj]Y)I-~
nEndPos = new long[nCount]; B(tLV9B3Q
for(int i=0;i<nStartPos.length;i++) C\"nlNKw
{ qw^kA?
nStartPos = input.readLong(); We%HdTKT
nEndPos = input.readLong(); .*FBr7rE\
} NGQBOV
input.close(); A|jmp~@K)+
} XC44]o4jx
catch(IOException e){e.printStackTrace ();} '-9B`O,&
catch(Exception e){e.printStackTrace ();} #snwRW>=[
} Xwz9E!m
F}9!k LR
xvo""R/g8
private void processErrorCode(int nErrorCode) pJ8;7u
{ U\OfB'Dn
System.err.println("Error Code : " + nErrorCode); TCShS}q;%
} z[Sq7bbYO
j v9DQr
Dp1FX"a)
//停止文件下载 O3ij/8f
public void siteStop() ivTx6-]
{ wJ.?u]f@
bStop = true; K]c|v i_D
for(int i=0;i<nStartPos.length;i++) scr`] tD
fileSplitterFetch.splitterStop(); pO]{Y?X:
e!V3/*F
#63)I9>
} 117`=9F
} R=Qa54
//负责部分文件的抓取 nsf.wHGZ"J
**FileSplitterFetch.java }ACWSkWK
*/ (!'=?B "
package NetFox; KWuc*!
Eo h4#fZ\N
,_SE!iL
import java.io.*; #B_Em$
import java.net.*; 8ckcTNPu
_6U=7<f
vP k\b 3E
public class FileSplitterFetch extends Thread { {T;A50
[\i0@
S"-q*!AhK
String sURL; //File URL D1xIRyc/
long nStartPos; //File Snippet Start Position k@}?!V*l
long nEndPos; //File Snippet End Position Evjvaa^
int nThreadID; //Thread's ID 0EWov~Y?
boolean bDownOver = false; //Downing is over lI,lR
boolean bStop = false; //Stop identical p~v rr 5
FileAccessI fileAccessI = null; //File Access interface sY|by\-c
%P3|#0yg0
#:q$sKQ_$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YJ6y]r K2,
{ RC[mpR;2
this.sURL = sURL; /R/\>'{E&c
this.nStartPos = nStart; dWR-}>
this.nEndPos = nEnd; _1>Xk_
nThreadID = id; Re[x$rw
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !' }
} Fa"/p_1
j<*
c@|!0 U%j
public void run() k4HE'WY
{ S*aMUV&
while(nStartPos < nEndPos && !bStop) ,Wbr; zb
{ 9`a1xnL
UrC>n
N}|<P[LW
try{ g$^:2MT"aQ
URL url = new URL(sURL); NA :_yA"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /m"#uC!\
httpConnection.setRequestProperty("User-Agent","NetFox"); pxGDzU
String sProperty = "bytes="+nStartPos+"-"; _ ^2\/@
httpConnection.setRequestProperty("RANGE",sProperty); # dA-dN
Utility.log(sProperty); o$4i{BL
{4C/ZA{|l
crwui8
InputStream input = httpConnection.getInputStream(); B,xohT
//logResponseHead(httpConnection); a+-X\qN
c}-ADr9
5%6{ ePh{
byte[] b = new byte[1024]; |>'.(
int nRead; 13JZ\`ceb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *ku}.n
{ _L^(CFE
nStartPos += fileAccessI.write(b,0,nRead); _ArN[]Z
//if(nThreadID == 1) x$SxGc~4gb
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <<SUIY@X
} $>M-oNeC
w7#9t
,P>xpfdK
Utility.log("Thread " + nThreadID + " is over!"); On`T pz/
bDownOver = true; 1(YEOZ
//nPos = fileAccessI.write (b,0,nRead); hvFXYq_[O
} qN=l$_UD
catch(Exception e){e.printStackTrace ();} Nn/f*GDvK
} HxAN&g*:
} 39yp1
#/,WgsAC
!T|q/ri
//打印回应的头信息 X]1Q# $b
public void logResponseHead(HttpURLConnection con) }Sx+:N*
{ uHQf<R$:
for(int i=1;;i++) u3k{s
{ xHpB/P~
String header=con.getHeaderFieldKey(i); c/'Cju W
if(header!=null) `w(~[`F t
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Sb|9U8h
Utility.log(header+" : "+con.getHeaderField(header)); >WZ_) `R
else 6OPYq*|
break; ,_iR
} 2uEvu
} O{{\jn|lR
uD0<|At/
\UEO$~Km
public void splitterStop() n5U-D0/Q
{ V4CL%i
bStop = true; JVe!(L4H
} q(XO_1W0V
oro^'#ki
DkA@KS1Dq
} ,7/F?!G!J
n# 4e1n+I
`Ei:Z%@7C
/* - %'ys
**FileAccess.java F8pP(Wl
*//文件访问(定位，写) .l:x!
package NetFox; =U`9_]~1c@
import java.io.*; 4Q?3gA1
*RllKPY)
N3m~nEj
public class FileAccessI implements Serializable{ "Nh}_jO
j&|>Aa${
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Z1Pdnc7S[
RandomAccessFile oSavedFile; K9=f`JI9
long nPos; zqlgJn
zf.&E3Sn
+d289"
public FileAccessI() throws IOException ,&ld:v?~
{ rk)h_zN
this("",0); -VafN
} Y7GHIzX
@\?QZX(H
"~,3gNTzV
public FileAccessI(String sName,long nPos) throws IOException %SC%#_7
{ 1$RUhxT
oSavedFile = new RandomAccessFile(sName,"rw"); ;8iK];^
this.nPos = nPos; f2]O5rXp
oSavedFile.seek(nPos); V+>.Gf
} pRc<U^Z.h
=%ry-n G
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public synchronized int write(byte[] b,int nStart,int nLen) N6<G`k,
{ \sc's7
int n = -1; >mCS`D8
try{ egn9O
oSavedFile.write(b,nStart,nLen); iZ;y(
n = nLen; m[$pj~<\
} %<yH6h*u
catch(IOException e) }HLV'^"k
{ )Q5ja}-{V
e.printStackTrace (); |HfN<4NL
} eZvG
uD8,E!\
oeA}b-Ct0
return n; Jf3xK"in
} <c_'(
SUaXm#9
c0.? d]
} !McRtxq?~
`Qxdb1>mjY
.?dYY;P
/* vcz?;lg
**SiteInfoBean.java 0UN65JBuD
*/ )ad6>Y
package NetFox; T(q/$p&q
w#w?Y!JXo
){FXonVP
public class SiteInfoBean { u0i;vO)MNt
w<$0n#5
4&_|myO&
private String sSiteURL; //Site's URL *<#$B}!{
private String sFilePath; //Saved File's Path IRY/0v
private String sFileName; //Saved File's Name .H7xG'$
private int nSplitter; //Count of Splited Downloading File p`T,VU&.
P+(q38f[
jImw_Q
public SiteInfoBean() N}X7g0>hV
{//nSplitter的缺省值为5 %WO4uOi:@
//default value of nSplitter is 5 #4wia%}u
this("","","",5); r NT>{
} a8v9j3.
f6U i~
K;P<c,9X/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N*6lyFcg
{ Y:KIaYkk
sSiteURL= sURL; %C=?Xhnv
sFilePath = sPath; /PTk296@
sFileName = sName; r~Vb*~U"
this.nSplitter = nSpiltter; [l:}#5\]4
7Ug^aA
vfpK|=[7o
} y8/+kn +
g>;u} +lO
Nny#}k Bt
public String getSSiteURL() =DLVWz/<
{ cFV3
return sSiteURL; ' "I-! +
} 7CV}QV}G
S0jYk(
qN@0k>11?
public void setSSiteURL(String value) RDsBO4RG
{ HWOOw&^<
sSiteURL = value; 1azj%WY
} Gcp!"y=i
"D[/o8Hk
/A"UV\H`f
public String getSFilePath() bd[%=5
{ DQyy">]Mh
return sFilePath; Lf0Wc'9{
} 1# ;`1i
^7,`6g
{qbxiL-
public void setSFilePath(String value) SioP`*,}
{ "e@?^J)
sFilePath = value; VB&`g<
} >8=rD
6o=Q;Mezl
_n=,H
public String getSFileName() -E,p[Sp
{ rls\3R(jt
return sFileName; l#^weXSlk
} "c*&~GSE4
r"_SL!,^
(^mpb
public void setSFileName(String value) _}3NLAqg
{ 3JXKpk?
sFileName = value; Kp?j\67S
} tL}_kK_!
.V.ga2+
*e%(J$t
public int getNSplitter() Gf\u%S!%
{ 8}>s{u;W
return nSplitter; 94b* !Z
} {~{</ g/
C)R#Om
P?$Iht.^
public void setNSplitter(int nCount) d[$YTw
{ O#3PUuE%d
nSplitter = nCount; f0]`TjY
} r0j+P%
} ' T%70)CM~
Ot([5/K
$i;_yTht
/* x A"V!8C
**Utility.java ^gdv:[m
*/ 7?a!x$-U(
package NetFox; E)]RQ~jY?
>@uFye$
B0$.oavC
public class Utility { k.Q4oyei
6y
,;~@t:!c
public Utility() E%vT(Kz
{ IW5N^J
d6+{^v$#
5~\GAjf
} |jJ9dTD8/
W $EAo+V
//线程睡眠 yR4++yk
public static void sleep(int nSecond) _a-At
{ n2;Vrs,<1&
try{ B(qwTz 51
Thread.sleep(nSecond); yYn7y1B
} %w#8t#[,6
catch(Exception e) c'&\[b(m
{ #B&%Y6E5
e.printStackTrace (); 8rpr10;U
} TT3\c,cs
} 3&"+)*/ m
r(DW,xoK0
//日志 `PI?RU[g*
public static void log(String sMsg) f}uW(:f
{ ]Yx&
System.err.println(sMsg); BfdS3VrZ/
} Xn*>qm
8Y&_X0T|
4M*!'sG\
public static void log(int sMsg) zsmlXyP'e!
{ Yrmd hSY
System.err.println(sMsg); PIZK*Lop
} KAR **Mp+
} #s3R4@{
JYO("f
:BpXi|n;
/* }E&48$0h
**TestMethod.java MVOWJaT(Aq
*/ -i*]Sgese
package NetFox; /j;HM[
erdA?
#v}pn2g%>
public class TestMethod { +5qY*$dn
,B,:$G<
L#Rj~&U
public TestMethod() 84f^==Y
{ ///xx/weblogic60b2_win.exe E4qQ
try{ S- JD}+9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); '-M9v3itC
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); VkZ3Q7d
SiteFileFetch fileFetch = new SiteFileFetch(bean); re@;6o
fileFetch.start(); EN;4EC7tE
} :XCRKRDLE
catch(Exception e){e.printStackTrace ();} eh}I?:(a?
cs7K^D;.V
G}#p4\/
} :[!b";pR
]Ia}H+&
NXSjN~aG2
public static void main(String[] args) (=t41-l
{ |0xP'(
new TestMethod(); OXD*ZKi8
} BT*{&'\/
} %hN7K
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