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)); G2c\"[N1/
} o?.VW/"
for(int i=0;i<nEndPos.length-1;i++) XJS^{=/
{ n36@&q+B&
nEndPos = nStartPos[i+1]; $mf6!p4
} ci 22fw0
nEndPos[nEndPos.length-1] = nFileLength; !@ AnwV]
} F<2gM#jLB
} O0pXHXSAL
k#mL4$]V5N
56NDU>j$
//启动子线程 7s:cg
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bsI?=lO
for(int i=0;i<nStartPos.length;i++) YVz,P_\(m
{ SST@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^tjM1uaZ5(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =PjdL32
nStartPos,nEndPos,i); >%t5j?p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i8R2Y9Q*O
fileSplitterFetch.start(); lqAv
} Nlc3S+$`z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =G'J@[d{d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1mfB6p1Z(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'Q*lp!2>
nEndPos = " + nFileLength); C'sA0O@O
// fileSplitterFetch[nPos.length-1].start(); $Nj'_G\}
R-f('[u
5g9K|-
//等待子线程结束 Q5Mn=
//int count = 0; Di$++T8"
//是否结束while循环 oMq:4W,
boolean breakWhile = false; [e:ccm
AVc|(~V
Ipow Jw^
while(!bStop) *;T HD>
{ i(q a'*
write_nPos(); OG7U+d6
Utility.sleep(500); 9Z3Y,`R,
breakWhile = true; =}SC .E\
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j(_6.zf
for(int i=0;i<nStartPos.length;i++) 8}Maj
{ JVPLE*T
if(!fileSplitterFetch.bDownOver) OF!n}.O(
{ :%zAX
breakWhile = false; $f6wmI;<y
break; ~}K$z
} 86Xf6Ea
} T(+*y
if(breakWhile) _C$SaQty[Q
break; 79'N/:.
dW|S\S'&
dJ{'b'#
//count++; <Lq.J`|+
//if(count>4) 9\6ZdnEKu,
// siteStop(); C7 9~@%T
} Rd1I$| Y
anUH'mcK*
<a D}Ko(
System.err.println("文件下载结束！"); 0INlo
} M8FC-zFs
catch(Exception e){e.printStackTrace ();} DCSTp2
} `hU2Ss~
gvxOo#8]
S%Z2J)H"
//获得文件长度 z}P1+Pm
public long getFileSize() _w9:([_
{ }_?FmuU
int nFileLength = -1; gBXbB9
try{ z"{Ji{>%=
URL url = new URL(siteInfoBean.getSSiteURL()); r5!Sps3B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~NwX,-ri
httpConnection.setRequestProperty("User-Agent","NetFox"); )TkXdA?.
82=>I*0Q
nrz2f7d$
int responseCode=httpConnection.getResponseCode(); 59a7%w
if(responseCode>=400) L'x[wM0w;
{ 0tN/P+!|
processErrorCode(responseCode); p=f8A71
return -2; //-2 represent access is error _^]:tL6
} &8Oy*'
XZpF<7l
%4h$/~
String sHeader; Ky[-ZQQo=5
<cR]-Yr~
,N2|P:x
for(int i=1;;i++) e5m-7{h@
{ d@<~u,Mt&F
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); CDRz3Hu U
//Utility.log(in.readLine()); h%%dRi
sHeader=httpConnection.getHeaderFieldKey(i); tt]ZGn*
if(sHeader!=null) 0BHSeO,
{ ]}N&I_mU
if(sHeader.equals("Content-Length")) ZG-[Gz
{ ZfWF2%]<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X}j_k=,C
break; 0tah$;c e
} }!5+G:JAh
} ]1i1_AR'`
else ':?MFkYC
break; =:7OS>x
} &^b mZj!
} $N17GqoC
catch(IOException e){e.printStackTrace ();} c UHKE\F
catch(Exception e){e.printStackTrace ();} Bpl(s+
~HyqHxy
J~1=?</
Utility.log(nFileLength); aEC&#Q(]q
0HS"Oxx'
>=3ay^(Y2D
return nFileLength; ^/v!hq_#%&
} x[eho,6)
3h>56{P
:~dI2e\:
//保存下载信息（文件指针位置） Kx5VR4f`J@
private void write_nPos() PLDp=T%
{ p |xMXoa`
try{ kX:d?*{KB
output = new DataOutputStream(new FileOutputStream(tmpFile)); ugMfpT)
output.writeInt(nStartPos.length); 81/t)Cp
for(int i=0;i<nStartPos.length;i++) %DF-;M"8
{ C\C*'l6d
// output.writeLong(nPos); M}b[;/~
output.writeLong(fileSplitterFetch.nStartPos); Zjkrne{
output.writeLong(fileSplitterFetch.nEndPos); 'hH3d"a^=
} 9..! g:
output.close(); *Z=:?4u
} j= Ebk;6p
catch(IOException e){e.printStackTrace ();} bG[)r
catch(Exception e){e.printStackTrace ();} N\WEp?%~
} j?cE0 hz
zXx)xIO
;bxL$1
//读取保存的下载信息（文件指针位置） 8X2NEVH]
private void read_nPos() YU24wTe;k
{ h(wu5G0C#u
try{ $ -n?q w
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Wk&g!FR
int nCount = input.readInt(); 9Fv VM9
nStartPos = new long[nCount]; 2K&5Kt/
nEndPos = new long[nCount]; SLMnEtyTS
for(int i=0;i<nStartPos.length;i++) Hwm]l`E]
{ mtg3}etA
nStartPos = input.readLong(); A +J&(7N
nEndPos = input.readLong(); `p)$7!
} G^=C#9c.m
input.close(); q+/7v9
} CHX- 4-84{
catch(IOException e){e.printStackTrace ();} 982n G-"
catch(Exception e){e.printStackTrace ();} R#i{eE*WF
} 4! V--F
u!WjG@
Yr9!</;T
private void processErrorCode(int nErrorCode) {E+o+2L
{ !XJS"owr
System.err.println("Error Code : " + nErrorCode); b )mU9
} \gjYh2>
Y$ To)qo
j)neVPf%v
//停止文件下载 w-M,@[G
public void siteStop() 8@Kvh|
{ \9GJa"xA`
bStop = true; *D$[@-7
for(int i=0;i<nStartPos.length;i++) 'qT[,iQ
fileSplitterFetch.splitterStop(); 9EqU 2~
1:r8p6
P7`sJ("#
} kX)Xo`^Ys
} 2PrUI;J$
//负责部分文件的抓取 .W)%*~ O!;
**FileSplitterFetch.java &6mXsx$
*/ 5bKm)|4z6
package NetFox; bF X0UE>
{"x8q
K~B@8az
import java.io.*; I"<ACM
import java.net.*; W~e/3#R\=
Z}Ld!Byz
9e*v&A2Y'
public class FileSplitterFetch extends Thread { O0VbKW0h3
3"ii_#1
}JePEmj
String sURL; //File URL (s2ke
long nStartPos; //File Snippet Start Position c0%.GcF0{
long nEndPos; //File Snippet End Position `"* ]C
int nThreadID; //Thread's ID ClvqI"Rd
boolean bDownOver = false; //Downing is over L)`SNN\ipR
boolean bStop = false; //Stop identical 93aRWEu3
FileAccessI fileAccessI = null; //File Access interface `/0S]?a.{B
;Iu}Q-b*
A/zZ%h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Rt^~db
{ @1UC9}>
this.sURL = sURL; /)Pf ]
this.nStartPos = nStart; e0ea2 2
this.nEndPos = nEnd; 7"c^$fj
nThreadID = id; x&SG gl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !leLOi2T
} 'nO%1BZj+
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RZ#~^5DiO
public void run() 3+j!{tJ z2
{ a$r<%a6
while(nStartPos < nEndPos && !bStop) B]o5HA<k
{ 2#y!(D8
V"T48~Ue
<FfdOK_
try{ I#m0n%-[
URL url = new URL(sURL); XAb!hc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >)sB#<e
httpConnection.setRequestProperty("User-Agent","NetFox"); ^-yEb\\i
String sProperty = "bytes="+nStartPos+"-"; 9J0JSy
httpConnection.setRequestProperty("RANGE",sProperty); dfss_}R
Utility.log(sProperty); 4._U
XsVp7zk\
y)B>g/Hoh
InputStream input = httpConnection.getInputStream(); e{"r3*
//logResponseHead(httpConnection); ]N\J~Gm
-9Ll'fbq
<^APq8>
byte[] b = new byte[1024]; hZ ve8J
int nRead; dP0%<Q|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X{j`H\'L
{ t%`GXJb
nStartPos += fileAccessI.write(b,0,nRead); dF?:&oP]
//if(nThreadID == 1) sKvz<7pag
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sfv{z!mo
} <ETR6r
f`dQ $Kh
bCv^za]P6
Utility.log("Thread " + nThreadID + " is over!"); f""+jc1
bDownOver = true; cM= ?{W7~
//nPos = fileAccessI.write (b,0,nRead); ?Z]5 [
} |@a.dgz,
catch(Exception e){e.printStackTrace ();} /i${[1
} p%8v+9+h2
} tocZO
y$f{P:!"{3
xMdbS4&!
//打印回应的头信息 (H\)BS7#R
public void logResponseHead(HttpURLConnection con) Y2)2 tzr]
{ U49#?^?
for(int i=1;;i++) am$-1+iX
{ Vl0 J!JK_
String header=con.getHeaderFieldKey(i); =%}++7#
if(header!=null) uTemAIp $u
//responseHeaders.put(header,httpConnection.getHeaderField(header)); COF_a%
Utility.log(header+" : "+con.getHeaderField(header)); /Lf+*u>"
else l Wa4X#~.
break; '_nJ DM
} U',9t
} |)7dh B
? ^EB"{
Y~|C]O
public void splitterStop() mkR1iY
{ }3"FQ/6C
bStop = true; o IUjd
} bR6g^Yf
zPC&p{S>
ranLHm.nB
} X/5\L.g2
Z`?Z1SBt
&_LFV@/
/* 5iG+O4n%
**FileAccess.java UJqDZIvC
*//文件访问(定位，写) vbDSNm#Yv
package NetFox; 3M;[.b
import java.io.*; FXHcy:)}G
C;u8qVI
X"S-f;b#
public class FileAccessI implements Serializable{ tAPr4n!
(&=<UGY(w
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #~ :j< =o
RandomAccessFile oSavedFile; 9WJS.\G^
long nPos; DPU%4te
i|@lUXBp
)CYm/dk
public FileAccessI() throws IOException )4[Yplo
{ U_-9rkUa
this("",0); M!{;:m28X!
} O3?3XB> <
hU:M]O0uw
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public FileAccessI(String sName,long nPos) throws IOException j2UiZLuV
{ (-RZ|VdYg
oSavedFile = new RandomAccessFile(sName,"rw"); y5td o'Ex
this.nPos = nPos; )9^0Qk' ]
oSavedFile.seek(nPos); BD)5br].
} rQ^X3J*`
y?ps+ce93
V/=NIeSE
public synchronized int write(byte[] b,int nStart,int nLen) {Z529Ns
{ :GXD-6}^|
int n = -1; (BB&ZUdyv
try{ KxEy N(n
oSavedFile.write(b,nStart,nLen); S(K}.C1x
n = nLen; B=>:w%<Ii
} #B;~i6h]
catch(IOException e) qoNVp7uv
{ %s+H& vfQs
e.printStackTrace (); y+ZRh?2
} MOiTzL*
mSw$? >
(&25 8i,
return n; }b//oe7
} Cr!}qZq
FC'v= *
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} W[5a'}OV
>i`V-"x
F"3LG"
/* %0>DjzYt
**SiteInfoBean.java $ BEIG@qG
*/ e{ce \
package NetFox; EFb1Y{u^\!
,a:!"Z^f
B74L/h
public class SiteInfoBean { U]Iypl`l
0i76(2
7J 0=HbH
private String sSiteURL; //Site's URL @Axwj
private String sFilePath; //Saved File's Path r%M.rYLG{
private String sFileName; //Saved File's Name So?ScX\lG
private int nSplitter; //Count of Splited Downloading File RXMzwk
u7rA8u|TO
:# 1d;jx
public SiteInfoBean() DNARe!pK
{//nSplitter的缺省值为5 QAp+LSm
//default value of nSplitter is 5 :UjF<V
this("","","",5); PT9,R^2T!
} C~16Jj:v
=%p%+F@RlW
X[Lwx.Ly8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mN>7vJ
{ eR'Df"+
sSiteURL= sURL; q*^Y8s~3I
sFilePath = sPath; uXs.7+f
sFileName = sName; %i7bkdcwk
this.nSplitter = nSpiltter; J! ;g.q
'6^20rj
v6gfyGCJ
} D1&%N{
P'.M.I@
bB|UQaCl
public String getSSiteURL() c: /Wk
{ `$IuN*
return sSiteURL; `m6>r9:
} ZRDY`eK
0KW@j>=jK
(dOC ^i
public void setSSiteURL(String value) 1_D|;/aI
{ QZcdfJck=+
sSiteURL = value; GpjyF_L
} %/l9$>{
8>Y
-ZTe#@J
public String getSFilePath() I~LN)hqdo
{ P@gVzx)M
return sFilePath; pYtG%<
} }b9"&io
(x}>tm
L*k[Vc
public void setSFilePath(String value) zEG6T*
{ e:SBX/\j
sFilePath = value; [dG&"%5vD
} Y\7>>?
w2-:!,X
<ptgFR+
public String getSFileName() V SJGp`
{ @;%+Ms
return sFileName; Eei"baw/
} sFqLxSo_I
cC{eu[ XW
Ls8@@b,t2
public void setSFileName(String value) TO&ohATp
{ "O{_LOJ
sFileName = value; nz72w_
} hE|Z~5\Y,>
p.{M sn
V3%"z
public int getNSplitter() h28")c.pH=
{ gyqM&5b
return nSplitter; rToZN!q\S
} ^ olaq(z
fE1B1j<
6jv_j[[
public void setNSplitter(int nCount) d~bZOy
{ XLEEd?Vct9
nSplitter = nCount; {!? @u?M
} ?LJDBN
} m3Mo2};?
VMry$
`Gct_6
/* Lk?%B)z
**Utility.java Y ^s_v_s
*/ ^/nj2"
package NetFox; -^ )0c
y v6V1gK
RrFq"
public class Utility { Rne#z2Ok
D?+\"lI
~SI`%^L
public Utility() !VaKq_W
{ 'q158x
$;kFuJF
fkLI$Cl
} qOA+ao
K U 2LJ_~Y
//线程睡眠 )?5027^
public static void sleep(int nSecond) kEQ1&9
{ "4Joou"U
try{ ;yfKYN[
Thread.sleep(nSecond); ;kSRv=S
} 3Go/5X/
catch(Exception e) -s?f<f{
{ =NHE_4/p
e.printStackTrace (); rF9|xgFK
} [}xVz"8V
} r]e1a\)r
,2t|(V*"&
//日志 $8/=@E{51
public static void log(String sMsg) baLO~C
{ [NG~FwpRf
System.err.println(sMsg); ~q5aMy d<
} UQ0Sfu
F52%og~N
zD#$]?@ b
public static void log(int sMsg) `SFA`B)[5@
{ AcZ{B<
System.err.println(sMsg); }BF!!*
} bQU{)W
} |PGF g0li
g=Gd|
l ga%U~
/* 0ge"ISK
**TestMethod.java [&_7w\m
*/ YmrrZ&]q
package NetFox; d=`a-R0
968<yO]
{6*$yLWK
public class TestMethod { \,UpFuU\
{Ad4H[]|]
gmdJ8$
public TestMethod() pUcN-WA
{ ///xx/weblogic60b2_win.exe %G'{G
try{ csh@C ckC8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _xKIp>A
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7+N0$0w%r
SiteFileFetch fileFetch = new SiteFileFetch(bean); lu_kir~
fileFetch.start(); gxKL yZO!
} :Dt]sE_d
catch(Exception e){e.printStackTrace ();} [b2KBww\
Z\lJE>1
,6J{-Iu
} CP]nk0
7 XNZEi9o
Ow#a|@
public static void main(String[] args) ]_"c_QG
{ X!aC6gujOH
new TestMethod(); @AB}r1E2
} _i3?;Fds
} M]Kxg;
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