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)); =O/v]B8"
} *C);IdhK%y
for(int i=0;i<nEndPos.length-1;i++) Tb:6IC7="
{ ~ o=kW2Y
nEndPos = nStartPos[i+1]; U7''; w
} Zi?:< H}
nEndPos[nEndPos.length-1] = nFileLength; -^Qm_lN
} &+0?Xip{Z
} 8<x& Xd
j&u/T
6p9 {z42
//启动子线程 hSz_e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; '#C5m#v
for(int i=0;i<nStartPos.length;i++) _T_6Yl&cf)
{ `mH]QjAO
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AJ3%Z$JJ;s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6zi 5#23
nStartPos,nEndPos,i); (tyky&$!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GExr] 2r
fileSplitterFetch.start(); p, T4BO
} 34QW^{dgE
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I7W`\d)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^T#jBqe
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W&k@p9
nEndPos = " + nFileLength); S17;;w0
// fileSplitterFetch[nPos.length-1].start(); S,EL=3},=
*07?U")
:p%#U$S4
//等待子线程结束 +z[+kir
//int count = 0; "@^Q"RF
//是否结束while循环 UhJ{MUH`
boolean breakWhile = false; SOZs!9oi
yDJy'Z_F{
Gr>CdB>~+
while(!bStop) S['cX ~
{ ol K+|nR
write_nPos(); I$R1#s
Utility.sleep(500); hQ}_(F_H
breakWhile = true; z%1e>`\E
^f57qc3nF
[mQdc?n\
for(int i=0;i<nStartPos.length;i++) Y/5(BK)
{ MsZx 0]
if(!fileSplitterFetch.bDownOver) $o0.oY#
{ G3 |x%/Fbp
breakWhile = false; ,!,tU7-H
break; `kE7PXqa
} w+r).PS}C
} D2GF4%|
if(breakWhile) }'?qUy3x
break; 8A5/jqnqt
x4/{XRQ
6{{<+ o
//count++; {kBsiSvsA;
//if(count>4) 5dhy80|g]
// siteStop(); oaZdvu@y
} C_'EO<w$
E[7E%^:Mg
q(X7e
System.err.println("文件下载结束！"); WNZYs
} V= -
catch(Exception e){e.printStackTrace ();} *o38f>aJl
} R(*t1R\
RO|8NC<oj
-Lq2K3JHyn
//获得文件长度 V1,/qd_
public long getFileSize() g*(z.
{ LuHRB}W
int nFileLength = -1; ;aj;(Z.p)
try{ AloL+eN@
URL url = new URL(siteInfoBean.getSSiteURL()); ^_i)XdPU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b;{"@b,Y
httpConnection.setRequestProperty("User-Agent","NetFox"); Zk/ejhy0
`N&*+!O%
^{{a v?h
int responseCode=httpConnection.getResponseCode(); q)f_!N
if(responseCode>=400) Bz <I7h
{ )0/*j]Kf
processErrorCode(responseCode); mE5{)<N:C
return -2; //-2 represent access is error iE}] E
} / Y od
6VC|] |*
3y+~l H:
String sHeader; MPDRMGR@i
h_{f_GQ"
]8fn1Hx\
for(int i=1;;i++) ?wv^X`Q*~
{ ^EKRbPA9:<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qH5nw}]
//Utility.log(in.readLine()); Jfk#E^1
sHeader=httpConnection.getHeaderFieldKey(i); NJ+$3n om
if(sHeader!=null) vy}_aD{B
{ h`n '{s
if(sHeader.equals("Content-Length")) jpO0dtn3=
{ KS<@;Tt
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :V5 Co!/+
break; BWQ`8
} SMIDW}U2S
} <F(S_w62
else [qW%H,_
break; |!9xL*A
} bS2g4]$'po
} {lH'T1^m
catch(IOException e){e.printStackTrace ();} ?O+.
catch(Exception e){e.printStackTrace ();} &6C]|13;
tq~4W% p/
l^}u S|c(
Utility.log(nFileLength); xs\<!
s+v9H10R
/&Cq-W
return nFileLength; 1U#W=Fg'
} _B#x{ii
jrFPd
/FE+WA}r
//保存下载信息（文件指针位置） #*/nUbsg
private void write_nPos() =1dczJHV
{ wn?oHz*
try{ }nX0h6+1
output = new DataOutputStream(new FileOutputStream(tmpFile)); dQ7iieT
output.writeInt(nStartPos.length); wM4{\ f\
for(int i=0;i<nStartPos.length;i++) Tx~w(A4:
{ $kxP5q%9
// output.writeLong(nPos); $u.rO7)
output.writeLong(fileSplitterFetch.nStartPos); Z^2SG_pD
output.writeLong(fileSplitterFetch.nEndPos); x?V^l*
} t6\H
output.close(); %hN>o)
} P7b"(G%
catch(IOException e){e.printStackTrace ();} g%"SAeG<K
catch(Exception e){e.printStackTrace ();} l[IL~
} |n)4APX\Q
F<4:P=
yna!L@ *@,
//读取保存的下载信息（文件指针位置） ,hu@V\SKv
private void read_nPos() HZ%V>88
{ wkGr}
try{ u&1M(~Ub=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i8k} B o
int nCount = input.readInt(); fMFkA(Of^
nStartPos = new long[nCount]; &"JC8
nEndPos = new long[nCount]; ^7/v[J<<
for(int i=0;i<nStartPos.length;i++) S+~;PmN9qL
{ x%r$/=
nStartPos = input.readLong(); (kB
nEndPos = input.readLong(); ;$6L_C4B
} .pWRV<25
input.close(); b#p0s?*
} uP%VL}%0
catch(IOException e){e.printStackTrace ();} ed/B.SY
catch(Exception e){e.printStackTrace ();} hBX.GFnw
} gEsD7]o(=
?_d>-NC
%;h1n6=v2
private void processErrorCode(int nErrorCode) s=-?kcoJ2d
{ 6]%=q)oL[
System.err.println("Error Code : " + nErrorCode); P8ej9ULX,
} @}H'2V
MYvz%7
t2{(ETV
//停止文件下载 -e(<Jd_=
public void siteStop() -s2)!Iko&
{ *Vq'%b9
bStop = true; Qc-W2%
for(int i=0;i<nStartPos.length;i++) l<uI-RX"
fileSplitterFetch.splitterStop(); Uz,P^\8^$
Jj[3rt?8
Mn/
} gizY4~ j
} 1}|y^oB\-
//负责部分文件的抓取 FT~c|ep.
**FileSplitterFetch.java M !"Q7>d
*/ mfI[9G
package NetFox; Bf00&PE;
2=;ZJ
u`Nrg<
import java.io.*; ";(m,if-
import java.net.*; qXq#A&
nbP}a?XC
:KvZP:T
public class FileSplitterFetch extends Thread { _ymSo`IvR
cJq{;~
6x(b/`VW
String sURL; //File URL @q<h.#9
long nStartPos; //File Snippet Start Position !gLJBp
long nEndPos; //File Snippet End Position }0E@eL
int nThreadID; //Thread's ID \R@}X cqZ
boolean bDownOver = false; //Downing is over <ZZfN@6
boolean bStop = false; //Stop identical P;25F
FileAccessI fileAccessI = null; //File Access interface hl**G4z9q
GYIQ[#'d7
A@lM=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |>j^$^l~
{ HI D6h!
this.sURL = sURL; ~!TrC<ft
this.nStartPos = nStart; =r]_$r%gR
this.nEndPos = nEnd; ^8oN~HLZ
nThreadID = id; AX@bM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mXJG &EA
} 79)iv+nf\l
%`G}/"
mL}Wan
public void run() Iu~(SKr=|$
{ \J(~ Nv5!
while(nStartPos < nEndPos && !bStop) nSo.,72
{ `ZC -lAY
{yf,:5
<]S M$)=D
try{ nrpbQ(zI*
URL url = new URL(sURL); T[},6I|!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A;C4>U Y
httpConnection.setRequestProperty("User-Agent","NetFox"); O[1Q#
String sProperty = "bytes="+nStartPos+"-"; ,82?kky
httpConnection.setRequestProperty("RANGE",sProperty); 2-g 5Gb2|
Utility.log(sProperty); d<\X)-"
+BI%.A`2
:Oj!J&A
InputStream input = httpConnection.getInputStream(); 6S%KUFB+e
//logResponseHead(httpConnection); :5^5l
'g)5vI~'
TffeCaBv
byte[] b = new byte[1024]; }/NL"0j+4
int nRead; :8)3t! A
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u?g;fh6
{ +)( "!@
nStartPos += fileAccessI.write(b,0,nRead); K nn<q=';G
//if(nThreadID == 1) UG}"OBg/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =x^IBLHN
} 1?p:66WmR
ABtv|0K
) { "}bMf
Utility.log("Thread " + nThreadID + " is over!"); +Sv2'& B
bDownOver = true; Sf`?j
//nPos = fileAccessI.write (b,0,nRead); 2rP!]
} zBrqh9%8e
catch(Exception e){e.printStackTrace ();} i"!j:YEo
} LGRhCOP:
} G @L`[Wu
r`0oI66B/
![%:X)?
//打印回应的头信息 G8W^XD
public void logResponseHead(HttpURLConnection con) :Ot5W
{ a!x?Apww
for(int i=1;;i++) 4NFvX4
{ ]ao%9:P;
String header=con.getHeaderFieldKey(i); n)]u|qq
if(header!=null) ug`Jn&x!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x2]chN
Utility.log(header+" : "+con.getHeaderField(header)); jA%R8hdr_
else .YS48 c
break; Bb5RZ#oa
} ^j_t{h)W(0
} PTA_erU
vN)l3
Kzfy0LWM
public void splitterStop() #|l#
{ g31\7\)Ir
bStop = true; 6O'B:5~[2
} eNt1P`2[
LCpS}L;
? i|LO
} 5m6I:s`pK
s)~H_,
R?,XSJ
/* ;&RHc#1F
**FileAccess.java /(ArA=#
*//文件访问(定位，写) _H2%6t/V
package NetFox; 9[\$\l
import java.io.*; 'F8:|g
2I~a{:O
5fhe{d"si
public class FileAccessI implements Serializable{ ?)c9!hR
/kd6Yq(y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ud,_^Ul
RandomAccessFile oSavedFile; 0R?LWm j
long nPos; ->YF</I
a: OuDjFp
h IUO=f
public FileAccessI() throws IOException [E%Ov0OC
{ I9r> 3?
this("",0); p8u-3
} cf1GA
jP"='6Vrw
)VR/a
public FileAccessI(String sName,long nPos) throws IOException W\yaovAt
{ =_dqoAF
oSavedFile = new RandomAccessFile(sName,"rw"); %MUwd@,
this.nPos = nPos; <~!R|5sK
oSavedFile.seek(nPos); +D+Rf,D
} w=75?3c7F
2SVJKX_V+
/3v`2=b
public synchronized int write(byte[] b,int nStart,int nLen) L[:b\O/p,
{ 3/((7O[
int n = -1; < G:G/
try{ ob.=QQQs
oSavedFile.write(b,nStart,nLen); w!^{Q'/,Q
n = nLen; PP)-g0^@
} W[tX%B
catch(IOException e) ::rKW*?
{ -}*YfwK
e.printStackTrace (); MXU8QVSY"
} 41`&/9:"_M
4m$Xjj`vE
"*aL(R
return n; dD8f`*"*=
} ~~'UQnUN4
zc#aQ.
5S?+03h~
} [S!_ubP5
)o8]MWT\;
pO_L,~<
/* ({AqL#x`u
**SiteInfoBean.java | sio:QP
*/ =XT}&D6
package NetFox; ~<#!yRy>r
U#!f^@&AB
!G3d5d2)C
public class SiteInfoBean { 07L1 "
/"<o""<]
zcNv T
private String sSiteURL; //Site's URL 42: 6=\
private String sFilePath; //Saved File's Path ;4 ON
private String sFileName; //Saved File's Name gNG_,+=!
private int nSplitter; //Count of Splited Downloading File ]RJcY1
m0k~8^L@f
fgSe]q//
public SiteInfoBean() _7"G&nZ0
{//nSplitter的缺省值为5 Pb^Mc <j
//default value of nSplitter is 5 ("L&iu\`@
this("","","",5); Bzw!,(u/ "
} 4U;6 2 jq
k/ 9S
^B|Q&1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B@W`AD1^{
{ @ukIt
sSiteURL= sURL; !h0#es\
sFilePath = sPath; tb-:9*2j-
sFileName = sName; AG$S;)Yl9c
this.nSplitter = nSpiltter; A<VNttgG
amn\#_(
*g<D p2`
} n_/_Y>{M0
hVB^:
P+~{q.|._c
public String getSSiteURL() C"P40VQoo
{ VY5/C;0^h
return sSiteURL; Je#vl4<L
} X^U)j N2
j[fVF3v
TYQ7jt0=.-
public void setSSiteURL(String value) 9_z u*
{ ,5_Hen=PI
sSiteURL = value; ./009p
} Wb/q&o
zMkjdjb
sacaL4[_<
public String getSFilePath() jz%%r Q(
{ i0%S6vmaS
return sFilePath; 7aJLC!
} ^$7Lmd.qI
N{u4
lIg;>|'Z5&
public void setSFilePath(String value) j~eYq
{ 6mnj!p]3
sFilePath = value; xi.L?"^/!
} y-TS?5Dr]
L`$MOdF{_
rVx%"_'*-
public String getSFileName() #mNM5(o
{ i%8I (F
return sFileName; w>:~Ev]
} ]e'Ol$3U9=
MHv2r
S'NZb!1+
public void setSFileName(String value) X/_e#H0
{ w~eF0{h
sFileName = value; a+TlZE>8
} pFLR!/J
9~^%v zM
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public int getNSplitter() 4,!S?:7
{ )pS1yYLj
return nSplitter; 4|ryt4B
} =#AeOqs( q
cvR|qHNX
!}D!_z,)u
public void setNSplitter(int nCount) +)#d+@-
{ P~V0<$C
nSplitter = nCount; q^ {Xn-G
} >g]S"ku|
} aN7VGc
/hPgOaB
V=pg9KR!T
/* T>l=0a #
**Utility.java W2VH?-Gw
*/ -vcHSwGb
package NetFox; (%huWW j
<n iq*
5G@z l
public class Utility { ^FJ=/#@T
;&Q8xC2
}xx[=t=nUf
public Utility() IS`1}i$1%
{ Ixhe86-:T
@;iW)a_M
6% @@~"
} ;?>xuC$
+1j@n.)ft
//线程睡眠 #2thg{5
public static void sleep(int nSecond) Vx5ioA]{
{ Iz/o|o]#
try{ 8}3dwr;-
Thread.sleep(nSecond); c7mIwMhl~
} X'4g\)*
catch(Exception e) / c1=`OJ
{ aVI/x5p~
e.printStackTrace (); zPp?D_t
} YN1P9j#0d
} d`D<PT(\
)GDP?Nc<Ik
//日志 lE~5 b
public static void log(String sMsg) }(h_ztw
{ >t|u 8/P
System.err.println(sMsg); =.9L/74@
} Xqt3p6
uXiAN#1
<StyO[
public static void log(int sMsg) G992{B
{ Y27x;U
System.err.println(sMsg); {AbQaw
} @EZ@X/8{&
} 5Z]zul@+*
:-B,Q3d
zY\pZG
/* 1ID0'j$
**TestMethod.java 7mipj]
*/ X\tE#c&K
package NetFox; H]V@Q~?e
{VBx;A3*I
29DYL
public class TestMethod { xc.(-g[
jm1f,=R
5mwtlC':l?
public TestMethod() :kUZNw'Bi
{ ///xx/weblogic60b2_win.exe F-?K]t#
try{ iUl5yq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .4c* _$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); YPQ&hEu0
SiteFileFetch fileFetch = new SiteFileFetch(bean); tMxa:h;/x
fileFetch.start(); vT)(#0>z
} R=g~od[N_
catch(Exception e){e.printStackTrace ();} 7iCH$}
gs)wQgJ[
!|hxr#q=4
} >p4#AfGF
M>+FIb(
4LqJ4jo
public static void main(String[] args) }J27Y;Zp9
{ {-*+G]
new TestMethod(); (Zi(6 T\z
} kwRXNE(k]_
} tz&'!n}
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