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)); W=\45BJ
} T$*#q('1"}
for(int i=0;i<nEndPos.length-1;i++) 0t2n7Y?N
{ ^50\c$
nEndPos = nStartPos[i+1]; AS/z1M_U
} yyM`J7]J
nEndPos[nEndPos.length-1] = nFileLength; DLD5>
} BI+x6S>d
} P`AW8Y6o
=2e{T J/
~'w]%rh!
//启动子线程 3wN{k\ns
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q)2i{\GPVn
for(int i=0;i<nStartPos.length;i++) =buarxk
{ #MUY!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #T++5G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K8RV=3MBLD
nStartPos,nEndPos,i); l-$5CO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U<I]_]
fileSplitterFetch.start(); t 09-y
} ?.^n,[2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l4*vM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _0"s6D$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bi[g4,`Z;
nEndPos = " + nFileLength); xq&r|el
// fileSplitterFetch[nPos.length-1].start(); 1 RVs!;
d'@i8N["{
W<>R;~)
//等待子线程结束 W0XfU`
//int count = 0; W5Vh+'3
//是否结束while循环 mjKu\7F
boolean breakWhile = false; QB;jZpF
G124!^
KW(^-:wmr
while(!bStop) oaG;i51!
{ <FfmDR
write_nPos(); 0( q:K6zI}
Utility.sleep(500); )3.=)?XW
breakWhile = true; |cgc^S/~H
{$Z S 27
oc;4;A-;`c
for(int i=0;i<nStartPos.length;i++) DO6 pv
{ xM=?ES
if(!fileSplitterFetch.bDownOver) Jk;dtLL}4
{ QXEz[R
breakWhile = false; ~rlPS#]o
break; !GnwE
} 1>L8EImx]V
} Dg*'n
if(breakWhile) kK=f@l
break; mcTC'. 9
E8L\3V4
||Vx:(d7D&
//count++; Qt>Bvu Q
//if(count>4) x27$h)R0v
// siteStop(); ;$3epP
} T_[
`6<Qb=
<Vl`EfA(
System.err.println("文件下载结束！"); <l5s[
} T%4yPmY
catch(Exception e){e.printStackTrace ();} >4bWXb'S}C
} o:`^1
`=%G&_3_<
8ib e#jlg
//获得文件长度 |? rO
public long getFileSize() g%okYH?
{ Pq1j
int nFileLength = -1; Kx02 2rgDU
try{ /0b7"Kr
URL url = new URL(siteInfoBean.getSSiteURL()); j\iNag(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ySHpN>U
httpConnection.setRequestProperty("User-Agent","NetFox"); ^O<@I
Y>x3`f]
a]!u go}
int responseCode=httpConnection.getResponseCode(); eOahr:Db
if(responseCode>=400) 1BSn#Dnj
{ Vi#[kn'
processErrorCode(responseCode); wb ^>/
return -2; //-2 represent access is error 6Ev+!!znu
} 5xQ5)B4k
WO$8j2!~#
F`>qg2wO
String sHeader; ?}HZJ@:lB
G"ixw
0-p %.}GE
for(int i=1;;i++) 5t|$Yt[
{ Q)\[wYMt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h{ZK;(u$
//Utility.log(in.readLine()); r,q.RWuII
sHeader=httpConnection.getHeaderFieldKey(i); Y$_^f*sFn
if(sHeader!=null) ,(f({l[J}
{ 6=96^o*
if(sHeader.equals("Content-Length")) !-t"}^)
{ f|Nkk*9$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >7z(?nQYT^
break; n[\L6}
} nfh<3v|kvR
} !QCErE;r
else h6?o)Q>N
break; pZ]&M@Ijp
} <) -]'@*c
} 5=V29
catch(IOException e){e.printStackTrace ();} SNf~%B?`L
catch(Exception e){e.printStackTrace ();} &yI>A1
Oj8D+sC{
jQ8 T
Utility.log(nFileLength); 9%2he)Yqc
92~$Qa\S!
ZCA= n
return nFileLength; @2`nBtk
} ng9_c
2InM(p7j~K
u+c2 m
//保存下载信息（文件指针位置） .g94|P
private void write_nPos() _#we1m
{ -s\R2_(
try{ [E/. r{S
output = new DataOutputStream(new FileOutputStream(tmpFile)); eN`G2eE
output.writeInt(nStartPos.length); aSI%!Vg.
for(int i=0;i<nStartPos.length;i++) i=&]%T6Qk
{ )1 QOA
// output.writeLong(nPos); FGeKhA 8jT
output.writeLong(fileSplitterFetch.nStartPos); aGAr24]y
output.writeLong(fileSplitterFetch.nEndPos); fcy4?SQ.<i
} /N,\st
output.close(); [fY7|
} 7jGfQ
catch(IOException e){e.printStackTrace ();} 0}po74x*r
catch(Exception e){e.printStackTrace ();} CZ>Ujw=&k
} qRz /$|.
nRT]oAi
])q,mH
//读取保存的下载信息（文件指针位置） uX%$3k
private void read_nPos() w-C%,1F,/
{ TaF;PGjVw
try{ QB !%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <U8w#dc
int nCount = input.readInt(); 2*] [M,L0c
nStartPos = new long[nCount]; q s:TR
nEndPos = new long[nCount]; NC iBn>=:
for(int i=0;i<nStartPos.length;i++) SiJ{
{ 6PC?*^v
nStartPos = input.readLong(); wOLV?Vk
nEndPos = input.readLong(); "U$](k.<VA
} x:h)\%Dg<
input.close(); n/e,jw
} $GHi9aj_P
catch(IOException e){e.printStackTrace ();} M.bkFuh
catch(Exception e){e.printStackTrace ();} ?}= $zN
} jv6>7@<G
1=e(g#Ajn\
lXEnm-_
private void processErrorCode(int nErrorCode) ;P$ _:-C
{ qn'TIE.
System.err.println("Error Code : " + nErrorCode); Sr_hD5!
} F{_,IQ]U
OX?E3 <8`
L[<CEk
//停止文件下载 ='@k>Ka+
public void siteStop() rq1zvuUx
{ Z?WVSJUVf
bStop = true; s(e1kk}"
for(int i=0;i<nStartPos.length;i++) Fc=6*.hy
fileSplitterFetch.splitterStop(); 7]~|dc(
<9T,J"y
{,?Gj@$
} (y1S*_D
} @ZrNV*&<
//负责部分文件的抓取 Hs{x Z:
**FileSplitterFetch.java tu/4
*/ FlY"OU*
package NetFox; 2fNNdxdbT
,?`kYPZ
ly6dl
import java.io.*; :_`Yrx5
import java.net.*; n xR\tBv
=W>a~e]/
<fA}_BH%]
public class FileSplitterFetch extends Thread { ltMcEv-d0
0QxBC7`qp
t:xTmK&vt
String sURL; //File URL 8 qZbsZi4
long nStartPos; //File Snippet Start Position =k;X}/
long nEndPos; //File Snippet End Position OMd:#cWsQ
int nThreadID; //Thread's ID MBnxF^c&P
boolean bDownOver = false; //Downing is over K<%8.mZ7
boolean bStop = false; //Stop identical )-Z*/uF^
FileAccessI fileAccessI = null; //File Access interface a^ys7UV
l.Z+.<@
cr?ZXu_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1^ go)(Mx
{ }lCQ+s!
this.sURL = sURL; ]24]id
this.nStartPos = nStart; B\% Gp}
this.nEndPos = nEnd; G*~CB\K_
nThreadID = id; Xq"Es
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Dz/MIx
} 5PP^w~n
9[DlJ@T}
ePxAZg$ `>
public void run() Z&=Oe^
{ }mI0D>n
while(nStartPos < nEndPos && !bStop) ;7QG]JX
{ rFUd
:LC3>x`:
|34w<0Pc,
try{ {xTh!ih2-
URL url = new URL(sURL); ~=<uYv?0s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Cv4nl7A'
httpConnection.setRequestProperty("User-Agent","NetFox"); $iA:3DM07
String sProperty = "bytes="+nStartPos+"-"; /CbiYm
httpConnection.setRequestProperty("RANGE",sProperty); ,]y_[]636
Utility.log(sProperty); J aJ/|N
e AaS }g 0
+}:2DXy@
InputStream input = httpConnection.getInputStream(); 3df5 e0
//logResponseHead(httpConnection); 6E(..fo:"
_c-(T&u<
0%,?z`UY
byte[] b = new byte[1024]; CkNh3'<wg
int nRead; +Fh,!`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3II*NANeg
{ sE!g!ht
nStartPos += fileAccessI.write(b,0,nRead); u yE#EnsH
//if(nThreadID == 1) q-,`\ TS
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D=Yr/qc?
} rV?@Kgxi
+8"P*z,
bQPO'S4
Utility.log("Thread " + nThreadID + " is over!"); (m=1yj9
bDownOver = true; -rT#Wi
//nPos = fileAccessI.write (b,0,nRead); 2^nws
} ][YuJUK8
catch(Exception e){e.printStackTrace ();} Der'45]*^
} mX?t|:[b
} XN{zl*`
a:4!z;2 |
i CB:p
//打印回应的头信息 4Y4zBD=<
public void logResponseHead(HttpURLConnection con) H^vA}F`
{ 4$U^)\06W
for(int i=1;;i++) &5[+p{2
{ E]S:F3
String header=con.getHeaderFieldKey(i); K$r)^K=s
if(header!=null) 'Asr,[]?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @xBO[v
Utility.log(header+" : "+con.getHeaderField(header)); <Q`3;ca^
else \MPbG$ ^
break; 2]FRIy d
} tCPK_Wws?Z
} "5?1S-Vl
@gM}&G08
xVN!w\0
public void splitterStop() 3Wx\Liw,
{ C@<gCMj,"
bStop = true; #7}YSfm^6
} FU.?n)P
F[W0gjUc
z+CX$.Z
} <:mK&quf
<(yAat$H
Q("4R
/* `O;4b#!g
**FileAccess.java @Pi]kWW})
*//文件访问(定位，写) 3UKd=YsJ
package NetFox; Q}a(vlZ
import java.io.*; Z%=A[`5]
L]&y[/\E1
;d_<6|*M
public class FileAccessI implements Serializable{ <=w!:
!4 lN[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4gWlSm)
RandomAccessFile oSavedFile; Lw1[)Vk}E
long nPos; VUz+_)
o|#F@L3i
#hMkajG
public FileAccessI() throws IOException tF./Jx]_
{ 9\=SG"e(
this("",0); cqW(9A|8
} ZPz=\^
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[;ZC_fD
public FileAccessI(String sName,long nPos) throws IOException vF>]9sMv
{ (A=Z,ed
oSavedFile = new RandomAccessFile(sName,"rw"); $H]NC-\+>
this.nPos = nPos; aygK$.wos
oSavedFile.seek(nPos); cRNVqMpg
} GdrVH,j
S2W@;XvV
^\Q%VTM
public synchronized int write(byte[] b,int nStart,int nLen) ZvO1=* J,
{ ~`B]G
int n = -1; {Ve`VV5E
try{ pK"Z9y&
oSavedFile.write(b,nStart,nLen); In+2~Jw/2!
n = nLen; #^$_3AY
} F2EX7Crj
catch(IOException e) sB^ejH
{ ugTnz$
e.printStackTrace (); "pH;0[r]
} ?1] \3nj
U}5]Vm$]
D0TFC3.k}
return n; dxtG3
} 82?LZ?!PD
@L0)k^:
!(Q@1c&z
} >B*zzj
~,xso0
O'3/21)|y
/* 0($On`#
**SiteInfoBean.java 6E^9>
*/ | qelvK*
package NetFox; )ZFc5m^+u
DnW/q
&FYv4J
public class SiteInfoBean { `~41>mM%
&!M6{O=~
Rtl1eJ-
private String sSiteURL; //Site's URL q(1hY"S"}b
private String sFilePath; //Saved File's Path K]|hkp&
private String sFileName; //Saved File's Name 3*(><<ZC
private int nSplitter; //Count of Splited Downloading File a$bE2'cb
+kD JZ
+>$Kmy[3
public SiteInfoBean() yUO%@;
{//nSplitter的缺省值为5 Uty0mc(
//default value of nSplitter is 5 t%f>*}*P*
this("","","",5); sb?!U"v.'
} Gm0}KU
A:pD:}fm}D
?.beN[X
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) h|lH`m^
{ kXlI*h
sSiteURL= sURL; \|M[W~8
sFilePath = sPath; ,Ik~E&Ku2'
sFileName = sName; `@vksjxu
this.nSplitter = nSpiltter; [~`p~@\+
iU3PlF[B/o
RUVrX`u*(
} <p2\;\?4z
l7IF9b$c
2pP"dX
public String getSSiteURL() >xsY"N&1i'
{ s|TO9N)pO
return sSiteURL; }"v#_vJfz7
} %,aSD#l`f
x{Dw?6TP
'SrDc'?
public void setSSiteURL(String value) ua_,c\iL
{ q]SH'Wd
sSiteURL = value; Z$6B}cz<
} ];N/KHeZ
PpF`0w=1%l
av:%wJUl,$
public String getSFilePath() ld 1[Usaq
{ <JvYCWX`
return sFilePath; cjd-B:l
} S?VKzVDB.S
2t>>08T
~d ~oC$=TC
public void setSFilePath(String value) d5R2J:dI
{ %Q;:nVt
sFilePath = value; ,\d03wha
} eW}-UeT
F6:LH,~8
pigu]mj
public String getSFileName() If8 ^
{ wub7w#
return sFileName; Be<bBKQb
} `49!di[
3Ljj|5.q
^BW8zu@=O
public void setSFileName(String value) wgq=9\+&
{ wnQi5P+
sFileName = value; s*eM}d.p
} ")nKFs5
%/hokyx
R$+"'N6p
public int getNSplitter() 'GO*6$/
{ ,Z7Ky*<j
return nSplitter; Fx)><+-
} VD =f 'D
#c'}_s2F[
aQzmobleep
public void setNSplitter(int nCount) {BJH}vV1)
{ #Pg?T%('`
nSplitter = nCount; |It{L0=U
} !d[]Qt%mA
} rhGB l`(B
t^%)d7$
s:z
/* _)4zm
**Utility.java BIg2`95F|
*/ x@pzgqi3
package NetFox; #]^M/y h
s5MG#M 9
'RNj5r
public class Utility { &lxMVynL
KxfH6:\RB
9C5F#(uY
public Utility() ^W^Y"0y9`
{ ?iHcY,
yBv4 xKMH
NL!xkcXO
} 0TiDQ4}i[
z:)*Aobwv
//线程睡眠 Q^?$2ck=
public static void sleep(int nSecond) {?X +Yw
{ ;CV'
try{ Z 8GIZ
Thread.sleep(nSecond); w[EEA_\
} ^?0?*
catch(Exception e) %(s2{$3
{ ma"M?aM
e.printStackTrace (); A v;NQt8ut
} dKw[#(m5v
} %uo#<Ny/ I
c^5fhmlt
//日志 twaH20
public static void log(String sMsg) 2&AX_#P
{ P;|63"U
System.err.println(sMsg); V=Bmpg
} i=fhK~Jd
wGHVq fm5
^a!oq~ZSy
public static void log(int sMsg) ?3v-ppw%
{ sp0_f;bC
System.err.println(sMsg); ?;w\CS^Qu
} I^D*) z
} f&&Ao
C?6q]k]r
-:b<~S[
/* 'l-VWqR-
**TestMethod.java ?4Rq +
*/ LVL#qNIu
package NetFox; : >$v@d
(?.h<v1}
EvA8<o
public class TestMethod { " ;\EU4R
+hH7|:JQ
&@PAv5iNf
public TestMethod() A!$sOp
{ ///xx/weblogic60b2_win.exe j1ap,<\.k
try{ 90wnwz
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s;tI?kR>%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); DnF|wS
SiteFileFetch fileFetch = new SiteFileFetch(bean); -YipPo"a
fileFetch.start(); 0-d&R@lX.
} 1d&Q E\2}
catch(Exception e){e.printStackTrace ();} 0zA:?}
C"k]U[%{
kkj_k:Eah
} (YYwn@NGj
W)Yo-%
V<KjKa+sG
public static void main(String[] args) Xxm7s S
{ V:AA{<
new TestMethod(); ^[2siG
} ]Rmu+N|
} :/}=s5aQl/
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