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)); 'j}g
} ehE-SrkU'
for(int i=0;i<nEndPos.length-1;i++) -,^WaB7u\
{ uoHqL IpQ
nEndPos = nStartPos[i+1]; .U 39nd
} eES'}[W>
nEndPos[nEndPos.length-1] = nFileLength; as(*B-_n~
} >b>gr OX
} uJY.5w
!Av1Leb9$
+8f>^*:u
//启动子线程 d@ZoV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /ERNS/w
for(int i=0;i<nStartPos.length;i++) Zi/-~')E
{ 6 Uw;C84!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NI8~QeGah
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KzG_ <<
nStartPos,nEndPos,i); uf]Y^,2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E5gl^Q?Z
fileSplitterFetch.start(); $T),DUYO
} V9T 4+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +*C^:^jA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >$uUuiyL4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e\r7BW\Y
nEndPos = " + nFileLength); pDOM:lGya
// fileSplitterFetch[nPos.length-1].start(); oIb) Rq!m
Y 9i][
< eQ[kM
//等待子线程结束 5mavcle{4r
//int count = 0; sLi*SR
//是否结束while循环 Sph*1c(R
boolean breakWhile = false; |{f~Ks%
(B:uc_+
{2:d`fqD
while(!bStop) (;UP%H>
{ +i=p5d5
write_nPos(); C8.W5P[U
Utility.sleep(500); e!Br>^8l
breakWhile = true; %K zbO0
x> \Bxa8
E0YU[([G
for(int i=0;i<nStartPos.length;i++) U Du~2%
{ Cw#V`70a
if(!fileSplitterFetch.bDownOver) Lm|al.Z
{ Vv4H:BK$
breakWhile = false; SA+d&H}Fc
break; _CE9B e\
} M/#U2!iFk
} .S!-e$EJ
if(breakWhile) O>AFF@=
break; Pq?*C;D
v9rVpYc"
Q#pnj thM
//count++; OQFi.8
//if(count>4) -k{Jp/-D
// siteStop(); Cs4hgb|
} h0Jl_f#Y
}9CrFTbx;
([KN*OF
System.err.println("文件下载结束！"); XG&K32_fs
} X NE+(Bt
catch(Exception e){e.printStackTrace ();} t',BI
} v=p0 +J>
4SR(->@
lFfXWNb
//获得文件长度 gz61FW
public long getFileSize() 5B*qbM
{ o&$hYy"<.L
int nFileLength = -1; fHfY}BQS
try{ y5u\j{?Te
URL url = new URL(siteInfoBean.getSSiteURL()); )gXTRkmw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _~A~+S}
httpConnection.setRequestProperty("User-Agent","NetFox"); DYRE1!
Hku=pr3Gn
fsvYU0L
int responseCode=httpConnection.getResponseCode(); ~@P)tl>
if(responseCode>=400) H$tb;:
{ 5v9uHxy
processErrorCode(responseCode); S}7>RHe
return -2; //-2 represent access is error RmOyGSO
} 4seciz0?
Rp/-Pv
-H\,2FO
String sHeader; O2v.
5pJ*1pfeo
L~eAQR
for(int i=1;;i++) Mr*|9h
{ F=}Z51|:~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |scUo~
//Utility.log(in.readLine()); g.a| c\WH
sHeader=httpConnection.getHeaderFieldKey(i); H/J<Pd$p
if(sHeader!=null) U3F3((EYJ
{ vg(K$o{BT
if(sHeader.equals("Content-Length")) maDz W_3
{ *#2Rvt*Ox
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O,mip
break; Of`c`-<j
} l!IGc:
} kG^dqqn6
else Q4wc-s4RN
break; q#vlBL
} /6U 4S>'(
} };sMU6e
catch(IOException e){e.printStackTrace ();} <*Y'lV
catch(Exception e){e.printStackTrace ();} GBbhar},g
DB@EVH
;&,.TC?l
Utility.log(nFileLength); X/+OF'po
irMd jG
xK;e\^v
return nFileLength; "^%Z'ou
} (p |DcA]BX
h\y-L~2E
uA\J0"0;}
//保存下载信息（文件指针位置） \L[i9m|e
private void write_nPos() VPd,]]S5(
{ n+oDC65[
try{ <LA^%2jT
output = new DataOutputStream(new FileOutputStream(tmpFile)); -_~)f{KN@
output.writeInt(nStartPos.length); Vk7=7%xW
for(int i=0;i<nStartPos.length;i++) &qRJceT(
{ ~m`!;rE
// output.writeLong(nPos); V8"Wpl9Cz
output.writeLong(fileSplitterFetch.nStartPos); 0YS?=oi
output.writeLong(fileSplitterFetch.nEndPos); QIV%6q+*R
} s#^pC*,'
output.close(); k/lFRi-i
} I]uhi{\C
catch(IOException e){e.printStackTrace ();} @2e2^8X7f
catch(Exception e){e.printStackTrace ();} Pp_V5,i\
} 9Nt3Z>d
Ze ? g
@2' %o<lF
//读取保存的下载信息（文件指针位置） ^l!L)iw
private void read_nPos() !k<:k "7
{ ]rW8y%yD
try{ AS;.sjgk
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); G|9B)`S
int nCount = input.readInt(); z{?4*Bq
nStartPos = new long[nCount]; yP\Up
nEndPos = new long[nCount]; nq;#_Rkr
for(int i=0;i<nStartPos.length;i++) ]d'^Xs
{ rt b*n~
nStartPos = input.readLong(); Q$=*aUU%G
nEndPos = input.readLong(); RJc%, ]:
} X+ f9q0
input.close(); rsF:4G"%
} JBcY!dy-d
catch(IOException e){e.printStackTrace ();} \6sQJq
catch(Exception e){e.printStackTrace ();} 2QayM?k8
} e.;M.8N#SQ
)U(u>SV(\
^7u#30,}3~
private void processErrorCode(int nErrorCode) Dip*}8$o(w
{ vJCf~'
System.err.println("Error Code : " + nErrorCode); {}\CL#~y
} GLh]G(
D1X{:#|
]\;xN~l
//停止文件下载 'G#SLqZy
public void siteStop() A=`*r*
{ <qY5SV,
bStop = true; DQgH_!
for(int i=0;i<nStartPos.length;i++) h<3p8eB
fileSplitterFetch.splitterStop(); I@./${o
oR %agvc^^
CC8k&u,
} aRwnRii
} f7+Cz>R
//负责部分文件的抓取 r!K|E95oj9
**FileSplitterFetch.java ./w{L"E
*/ R6@uM<
package NetFox; ^:DyT@hQB5
N@1p]\
SrZ50Se
import java.io.*; 6?SFNDQ"C
import java.net.*; l3J$md|f
D4Sh9:\
%v4 [{ =fE
public class FileSplitterFetch extends Thread { \ 4gXY$`@
t[2i$%NVM
zj20;5o>U&
String sURL; //File URL xo~g78jm7,
long nStartPos; //File Snippet Start Position +,_c/(P
long nEndPos; //File Snippet End Position mk=#\>
int nThreadID; //Thread's ID S< x:t(
boolean bDownOver = false; //Downing is over 4/MNqit+
boolean bStop = false; //Stop identical 8:{q8xZ=k
FileAccessI fileAccessI = null; //File Access interface 3k{ @.V?]
A&N*F"q
n,nisS
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Yx1 D)
{ RvW.@#EH0
this.sURL = sURL; aZgNPw
this.nStartPos = nStart; )w"0w(
this.nEndPos = nEnd; yNva1I
nThreadID = id; 4<}A]BQVkJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 AMTslo
} 8"M<{72U]
Z[} $n-V
B>|5xpZM12
public void run() <]Y[XI(kr
{ z5EVG
while(nStartPos < nEndPos && !bStop) [hU=mS8=^
{ K0<yvew
kp`0erJqw
3*WS"bt
try{ F]5\YYXO
URL url = new URL(sURL); I:t^S.,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D[~}uZ4\
httpConnection.setRequestProperty("User-Agent","NetFox"); w3bIb$12
String sProperty = "bytes="+nStartPos+"-"; e2Jp'93o'
httpConnection.setRequestProperty("RANGE",sProperty); !6E:5=L^
Utility.log(sProperty); d@>\E/zA
}ywi"k4>
./.=Rw
InputStream input = httpConnection.getInputStream(); :[?!\m%0
//logResponseHead(httpConnection); %fpsc_
=pp:j`B9(
Z#7U "G-A
byte[] b = new byte[1024]; F5IZ"Itu(
int nRead; XGIpUz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JZ K7uB,X
{ xG%*PNM0q
nStartPos += fileAccessI.write(b,0,nRead); F+*Q <a4
//if(nThreadID == 1) %6]\^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4oJ$dN
} U**)H_S/~
Nza; O[
0yTQ{'Cc
Utility.log("Thread " + nThreadID + " is over!"); QUp?i
bDownOver = true; `a'`$'j
//nPos = fileAccessI.write (b,0,nRead); (1 yGg==W.
} 1S*P"8N}0h
catch(Exception e){e.printStackTrace ();} ~4^p}{
} @1.9PR$x
} ]fC7%"nB
][t6VA
owMmCR
//打印回应的头信息 oD,C<[(p
public void logResponseHead(HttpURLConnection con) UTX](:TC
{ Tc_do"uU
for(int i=1;;i++) pqq?*\W&[v
{ 7jT}{ x
String header=con.getHeaderFieldKey(i); Omb.53+
if(header!=null) ~B]jV$=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #eLN1q&Z
Utility.log(header+" : "+con.getHeaderField(header)); OPiaG!3<
else M.[wKGX(
break; K;C_Z/<%
} VN+\>j-
} KpGUq0d@
u _X}-U
5)*6V&
public void splitterStop() ^4UcTjh
{ pK"&QPv
bStop = true; D1ZC&B_}-
} /.v_N%*-v
4d-q!lRpa
:<UtHf<=k
} DZP*x
e>!E=J)j
[`9^QEj
/* +"Ub/[J{G1
**FileAccess.java 0BDoBR
*//文件访问(定位，写) cz>mhD
package NetFox; J{!'f| J
import java.io.*; |hD~6a
cIZ[[(Db
GEfY^!F+
public class FileAccessI implements Serializable{ U2UyN9:6F
Y"oDFo,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 k-vA#
RandomAccessFile oSavedFile; N"~ qoJO
long nPos; b-uZ"Kf^
:ln/`_
U1kh-8 :
public FileAccessI() throws IOException +Y;8~+
{ _<2RYXBC
this("",0); WP!il(Gr
} F-tFet
dFMAh&:>
?V?<E=13
public FileAccessI(String sName,long nPos) throws IOException l# BZzJ?~
{ ETg{yBsp
oSavedFile = new RandomAccessFile(sName,"rw"); HSC6;~U
this.nPos = nPos; Tplg2p%k
oSavedFile.seek(nPos); UeNF^6sWu0
} L5&K}F]r^
TR?Bvy2s:g
Kk>DYHZ6y
public synchronized int write(byte[] b,int nStart,int nLen) T,Fm"U6[(
{ ,0,Oe=d
int n = -1; ?#i|>MRR>
try{ kAt RY4p
oSavedFile.write(b,nStart,nLen); 18rp; l{
n = nLen; UtPwWB_YV
} I<KCt2:X
catch(IOException e) wE8]'o
{ ]6q*)q:`
e.printStackTrace (); lm!FM`m
} IG&B2*
IOS^|2:,
G-ZhGbAI7
return n; N-xnenci
} eZA6D\
q6Rw4
d&?F#$>7|
} \D ^7Z97
}\EL;sT
ys/vI/e\
/* t)KPp|&
**SiteInfoBean.java i!tc
*/ y{?Kao7Ij
package NetFox; N?zV*ngBS
c|+y9(0|y
*s~i 2}
public class SiteInfoBean { kM,@[V
0+rW;-_(
j+ I*Xw
private String sSiteURL; //Site's URL =^#0.
private String sFilePath; //Saved File's Path g(1"GKg3K
private String sFileName; //Saved File's Name <347 C{q
private int nSplitter; //Count of Splited Downloading File Vl-D<M+ih
!%X>rGkc
:)j7U3u
public SiteInfoBean() |K6nOX!i
{//nSplitter的缺省值为5 qR_SQ VN
//default value of nSplitter is 5 u6f4yQ
this("","","",5); A_aO}oBX
} fG3wc l~
PMQb\%iE"
G%Y*q(VrEu
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \_?yzgf
{ pTN%;`) {
sSiteURL= sURL; [+_\z',u
sFilePath = sPath; !eV^Ah>PZ
sFileName = sName; V@Ax}<$A
this.nSplitter = nSpiltter; 80dSQ"y
tD865gi
N=.}h\{0
} >}mNi:6xq
dWMccn;-m
3Nc'3NPQ'
public String getSSiteURL() e5QOB/e&
{ ]Kof sU_{
return sSiteURL; p1C_`f N,
} DZ,<Jmg&e*
SCqu,
av"Dljc
public void setSSiteURL(String value) 6V+V zDo
{ =P1RdyP
sSiteURL = value; ?U=mcdqd
} PKl]GegP
MK<
6^WiZ^~
public String getSFilePath() iOKr9%9?Z
{ y/z9Ce*>
return sFilePath; p!C_:Z5i
} c]S+70!n
',:3>{9
5aa}FdUq
public void setSFilePath(String value) kx:c*3q.k
{ S_a :ML<
sFilePath = value; 8moUK3w
} ?0? x+
7ZL,p:f
!Jk(&.
public String getSFileName() MiRibHXI,
{ fLLnf].O
return sFileName; 8}Fw%;Cb
} F">Nrj-bs
5`(((_Um+
Uf=vs(
public void setSFileName(String value) t`N ">c"
{ ,w,ENU0~f
sFileName = value; JHnk%h0
} '#;,oX~5
[Od>NO,n+]
vx({N?
public int getNSplitter() H(
{ d/"gq}NT
return nSplitter; er&uC4Y]a
} :!r9 =N9
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a7ub.9>
public void setNSplitter(int nCount) |Ba4 G`
{ 3?a0 +]
nSplitter = nCount; 53g8T+`\(
} >xhd[
} 67Af} >Q
x.jYip
6n2Vx1b
/* _C7abw-
**Utility.java n's2/9x
*/ x@{G(W:W
package NetFox; [Q2S3szbt6
7j9D;_(.^$
o=mq$Z:}
public class Utility { hNu>s
dSA [3V
x!Z:K5%O
public Utility() U08<V:~
{ wgSR*d>y*9
.0R/'!e
gJ)h9e*m^
} SX1Fyy6 w
y9l#;<b
//线程睡眠 P#vv+]/
public static void sleep(int nSecond) pIU#c&%<9
{ sRo<4U0M;l
try{ Thht_3_C,f
Thread.sleep(nSecond); ;-Y]X(z>
} |!jYv'%
catch(Exception e) ?~]1Gd
{ H{Y5YTg]
e.printStackTrace (); |k['wqn"
} W<cW;mO
} ^C,/T2>
7gZVg@
//日志 dw{#||
public static void log(String sMsg) ,q'gG`M N
{ 4 _c:Vl
System.err.println(sMsg); = C$@DNEc
} q>(I*=7
8JjU 9#
%%-U.
public static void log(int sMsg) _Vk,&'
{ ' q=NTP
System.err.println(sMsg); 7(+OsE
} R&x7Iq:=D
} m_r@t*
tLoD"/z
1O'*X
/* 2EqsfU* I
**TestMethod.java %1 VNP(E
*/ [#P`_hx
package NetFox; QBPvGnb
<De3mZb
C9z~)aL}7
public class TestMethod { :>er^\
`1[Sv"
@dT: 1s
public TestMethod() "[".3V
{ ///xx/weblogic60b2_win.exe iEJQ#5))0
try{ 1 ">d|oC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hklO:,`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <p L;-
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0imqj7L
fileFetch.start(); o,''f_tRQ|
} g_Dt} !A\B
catch(Exception e){e.printStackTrace ();} :zn ?<(sQ
8NF;k5
WT ~dA95
} 4f*Ua`E_
9^ *ZH1
cJ(zidf_$
public static void main(String[] args) YL&b9e4
{ (zTI)EV
new TestMethod(); Oz9Mqcx
} X-ki%jp3
} Zh~Lm
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