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)); (:>,u*x%
} Bn &Ws
for(int i=0;i<nEndPos.length-1;i++) q1KZ5G)6GJ
{ \}|o1Xh2
nEndPos = nStartPos[i+1]; k5kxQhPf
} |0f>aZ
nEndPos[nEndPos.length-1] = nFileLength; r<d_[?1N
} jIyB
} ~S,,w1`
#^A*
c$yk s
//启动子线程 }|8_9Rx0*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; cHk)i
for(int i=0;i<nStartPos.length;i++) AiO$<CS
{ }WH&iES@P
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &n8_0|gK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), d\gJ$ ~^K
nStartPos,nEndPos,i); m3/O.DY%0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [UWdW
fileSplitterFetch.start(); 9j6QX~,
} )O@]uY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |}di&y@-JI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `M^= D&Bf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", HK0!P*
nEndPos = " + nFileLength); YOmM=X+'H
// fileSplitterFetch[nPos.length-1].start(); 7Bd-!$j+
KJaXg;,H
yj.7'{mA
//等待子线程结束 !`Hd-&}bYz
//int count = 0; ~yW4)4k;b
//是否结束while循环 P 'od`
boolean breakWhile = false; T~##,qQ
DrY:9[LP
]Hefm?9*^
while(!bStop) j~jV'f.:H
{ =*c7i]@}
write_nPos(); .7avpOfz
Utility.sleep(500); #PH~1`vl
breakWhile = true; IS&ZqE(`e
NUWDc]@J*
]\hSI){
for(int i=0;i<nStartPos.length;i++) NRIG1v>
{ UMm!B`M
if(!fileSplitterFetch.bDownOver) biU^[g("
{ -7@/[9Gf`:
breakWhile = false; zGkS^Z=(
break; |8l<$J
} @v)p<r^M">
} :2rZcoNb.
if(breakWhile) 8"8t-E#?
break; S79;^X
eoG$.M"
|Sy<@oq
//count++; )I^7)x
//if(count>4) SBfT20z[
// siteStop(); yDegcAn?
} Kzm+GW3o[
AicBSqUke
3yU.& k
System.err.println("文件下载结束！"); (mTE;s(
} ~O oidKT
catch(Exception e){e.printStackTrace ();} $Y/9SV,
} ( +Q&[E"87
W_\5nF
c|B.n]Z
//获得文件长度 !h23cj+V
public long getFileSize() IYS)7`{]
{ SwTL|+u
int nFileLength = -1; mpU$+
try{ ,*&:2o_r
URL url = new URL(siteInfoBean.getSSiteURL()); _u5#v0Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $0>60<J
httpConnection.setRequestProperty("User-Agent","NetFox"); %7IugHH9y
p93r'&Q
t\k$};qJ
int responseCode=httpConnection.getResponseCode(); @hiCI.?X
if(responseCode>=400) /'l{E
{ `(ue63AZ
processErrorCode(responseCode); _/-jX
return -2; //-2 represent access is error 4U+xb>
} 7vrl'^1
|Mup8(gCk
[B#R94
String sHeader; 'MUv5Th
4ew" %Cs*
N~goI#4
for(int i=1;;i++) (_mnB W
{ bnq;)>&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'g=
//Utility.log(in.readLine()); cdl&9-}
sHeader=httpConnection.getHeaderFieldKey(i); Zw5Ni Xj
if(sHeader!=null) F4}]b(L
{ Z<1FSk,[
if(sHeader.equals("Content-Length")) "U>JM@0DNm
{ 0WZ_7C?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -Ta9 pxZk
break; 8dZSi
} LsqA**=
} hV8[@&Sx3
else B%)%
break; O`x;,6Vr
} 1PVtxL?1P
} xW)2<m6C&
catch(IOException e){e.printStackTrace ();} =9O^p@Q#W
catch(Exception e){e.printStackTrace ();} WM7oM~&{6
4B =7:r
nm5cpnNl
Utility.log(nFileLength); *4Thd:7 `
=n5zM._S-
%GjM(;Tk
return nFileLength; p{amC ;cI$
} =9'RM>
9YIM'q>`v
nBjqTud
//保存下载信息（文件指针位置） [R(`W#W
private void write_nPos() Y!~49<;
{ $+8cc\fq
try{ Pk{_(ybaY
output = new DataOutputStream(new FileOutputStream(tmpFile)); =9y[1t
output.writeInt(nStartPos.length); ?26I,:;
for(int i=0;i<nStartPos.length;i++) A!s`[2 Z
{ jSh5!6O
// output.writeLong(nPos); ddJQC|xR}
output.writeLong(fileSplitterFetch.nStartPos); >kj`7GA
output.writeLong(fileSplitterFetch.nEndPos); qON|4+~u%
} R&8Iz yM
output.close(); H[s(e56z
} 8ndYV>{f
catch(IOException e){e.printStackTrace ();} BZ94NOOdw
catch(Exception e){e.printStackTrace ();} fxgPhnaC>
} 4ni<E*
#C~+JL
rq8K_zp
//读取保存的下载信息（文件指针位置） <Swt);
private void read_nPos() Qi,j+xBp
{ [w>$QR
try{ 1-%fo~!l
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); a,@]8r-"
int nCount = input.readInt(); >:AARx%
nStartPos = new long[nCount]; XX7{-Yy
nEndPos = new long[nCount]; {@H6HqD
for(int i=0;i<nStartPos.length;i++) yzbx .
{ FOv=!'So
nStartPos = input.readLong(); *W4m3Lq
nEndPos = input.readLong(); 9_# >aOqL
} 7`-Zuf
input.close(); J`peX0Stl
} 3 R=,1<
catch(IOException e){e.printStackTrace ();} `YFtL
catch(Exception e){e.printStackTrace ();} 4x{0iav
} ~bM4[*Q7
wxR,OR
;,C)!c&
private void processErrorCode(int nErrorCode) WZ-s--n#
{ 0t^M3+nc
System.err.println("Error Code : " + nErrorCode); ?J%1#1L"/
} B-?6M6#
h;C5hU4P
L"E7#}
//停止文件下载 <;9I@VYK
public void siteStop() 0IwA#[m1`
{ :#LLo}LKp
bStop = true; T%.8'9
for(int i=0;i<nStartPos.length;i++) %824Cqdc
fileSplitterFetch.splitterStop(); 6*PYFf`
B8nf,dj?X
-E^vLB)O
} JmF l|n/H
} iQ tNAj
//负责部分文件的抓取 o1-m1<ft
**FileSplitterFetch.java 3B1XZm
*/ #ZJ _T`l
package NetFox; h%o%fH&F!
gy,ht3
Fu SL}P
import java.io.*; ZOft.P O
import java.net.*; In:9\7~jC
t9,\Hdo
X\`_3=
public class FileSplitterFetch extends Thread { K{x\4
g-Mj.owu=
X>1,!I9
String sURL; //File URL sT !~J4
long nStartPos; //File Snippet Start Position 3VsW@SG7N
long nEndPos; //File Snippet End Position WzPTFw[
int nThreadID; //Thread's ID -MW_|MG
boolean bDownOver = false; //Downing is over %z/hf
boolean bStop = false; //Stop identical 9i'jjN
FileAccessI fileAccessI = null; //File Access interface ; o?-yI&T*
=[H;orMr
6TQoqH8@U
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UR%/MV
{ ?+_Gs;DGVE
this.sURL = sURL; txJr;
this.nStartPos = nStart; 8e*,jH3
this.nEndPos = nEnd; ,p4&g)o
nThreadID = id; 2"0es40;0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7FzA*
} Of-Rx/
p6]7&{>
xO$lsZPG
public void run() $:cE ^8K
{ tR}MrM
while(nStartPos < nEndPos && !bStop) I~q#eO)
{ r;/4F/6"
gcE|#1>
J,V9k[88
try{ )2pbpbWX>
URL url = new URL(sURL); {J{+FFsr(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~rlB'8j(
httpConnection.setRequestProperty("User-Agent","NetFox"); ~?D4[D|sB
String sProperty = "bytes="+nStartPos+"-"; 9)y/:sO<P
httpConnection.setRequestProperty("RANGE",sProperty); dq7x3v^"ZG
Utility.log(sProperty); bHPYp5UwN
y-T| #
^M3~^lV
InputStream input = httpConnection.getInputStream(); )`SES."
//logResponseHead(httpConnection); !Nu<xq@!
?p9VO.^5
fdxLAC
byte[] b = new byte[1024]; 1QqYQafA
int nRead; 8B7cBkl:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e>7]w,*|
{ u}>#Eb
nStartPos += fileAccessI.write(b,0,nRead); |S_T^'<W
//if(nThreadID == 1) c]$i\i#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qHsUP;7
} FYOD Upn
,`wXg
us;YV<)d
Utility.log("Thread " + nThreadID + " is over!"); y)F;zW<+
bDownOver = true; _wC3kAO
//nPos = fileAccessI.write (b,0,nRead); ?Eg(Gu.J
} Q~814P8]
catch(Exception e){e.printStackTrace ();} FqkDKTS\&
} `sUZuWL_
} 7Ilm{@b=
N/]o4o
;KOLNi-B&
//打印回应的头信息 iDN;m`a
public void logResponseHead(HttpURLConnection con) r>dwDBE
{ _9faBrzd
for(int i=1;;i++) f_wvZ&
{ a#^B2
String header=con.getHeaderFieldKey(i); sJ#4(r`
if(header!=null) /|r^W\DV&x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -|kA)M[
Utility.log(header+" : "+con.getHeaderField(header)); TK5K_V*7
else j;%-fvd;
break; oE<`VY|
} Wc,_RN-
} *7*lE"$p
y#>,+a#5
LG-y]4a}
public void splitterStop() wQv'8A_}
{ ie;]/va
bStop = true; R#xCkl-
} ZZWD8AX
cnSJ{T
sqla}~CiX
} 'HT7_$?*
flk=>h|
rJPb 3F
/* K2he4<
**FileAccess.java 6^%UU o%
*//文件访问(定位，写) LL]zT H0
package NetFox; qgE 73.!`6
import java.io.*; /nyUG^5#{
4S,`bnmB
%F\?R[^5
public class FileAccessI implements Serializable{ O>SLOWgha
x6(~;J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t]>Lh>G
RandomAccessFile oSavedFile; &Q+Ln,(&L
long nPos; HKF H/eV
Kpb#K[(]&
>GQEqXs
public FileAccessI() throws IOException L~_9_9c
{ Z= jr-)kK
this("",0); g$( V^
} qi;f^9M%
OH;b"]
D0gZC
public FileAccessI(String sName,long nPos) throws IOException k:*S&$S!E
{ dArDP[w
oSavedFile = new RandomAccessFile(sName,"rw"); RD\
this.nPos = nPos; km)zMoE{c{
oSavedFile.seek(nPos); zfI>qJ+Nqt
} 8'~[pMn`
k9)jjR*XxG
6Pnk5ps }h
public synchronized int write(byte[] b,int nStart,int nLen) < XP9@t&
{ }~#pEX~j*
int n = -1; xB_!>SqF1U
try{ &Ts-a$Z7?S
oSavedFile.write(b,nStart,nLen); O_$m!5ug
n = nLen; zV:pQRbt.
} &$"i,~q^b
catch(IOException e) Xg<*@4RD8
{ SeHagKA
e.printStackTrace (); 9l}FU$
} t0z!DOODZP
~(x;5{
[E+$?a=
return n; HHiT]S9
} W- i&sUgy
Z^V6K3GSz-
N5*u]j
} cU ?0(z7
M(jgd
GN-mrQo
/* fNb`X
**SiteInfoBean.java i7ISX>%
*/ K3m]%m2\
package NetFox; vN|l\!~
{S,l_d+(
.7i` (F)
public class SiteInfoBean { 7nHF@Y|*"
.%.9n\b
,stN
private String sSiteURL; //Site's URL wSb1"a
private String sFilePath; //Saved File's Path 3= xhoRX
private String sFileName; //Saved File's Name /V8}eZ97
private int nSplitter; //Count of Splited Downloading File \zieyE
(Q%'N3gk
~\=1'D^6CK
public SiteInfoBean() 7:9.&W/KE
{//nSplitter的缺省值为5 L!=4N!j
//default value of nSplitter is 5 _7IKzUn9g[
this("","","",5); )N=NR2xBZ
} ,oaw0Vw
&C_'p{G
~vXaqCX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4D['^q
{ =Vy`J)z9
sSiteURL= sURL; &8%e\W\K:/
sFilePath = sPath; Y]{ >^`G
sFileName = sName; Swp;HW7x
this.nSplitter = nSpiltter; |AcRIq
fRy^Q_~,
g0>,%b
} e?_@aa9~@{
70f Klp
Vm(1G8 a
public String getSSiteURL() GDu~d<RH
{ 2R=DB`3
return sSiteURL; bhkUKxd
} SG-'R1 J
}:u~K;O87
= QQ5f5\l
public void setSSiteURL(String value) Y^ kXSU
{ vFE;D@bz:
sSiteURL = value; ta`N8vnf
} $-#Yl&?z9
58%#DX34M
Q-MQ9'
public String getSFilePath() X>NhZ5\
{ 1WY/6[
return sFilePath; Zm=(+ f
} 2>86oP&
mjWU0Gh%*
2Yp7
public void setSFilePath(String value) {]E+~%Va
{ f>piHh?
sFilePath = value; h3*Zfl<]
} 3pK*~VK
L:_bg8eD#
LbaK={tR
public String getSFileName() ogL EtqT
{ cU{e`<xjA
return sFileName; 7<%<Ff@^)O
} U f|> (C
.C2TQ:B,.
kGd<5vCs
public void setSFileName(String value) iXjo[Rz^C
{ OfctoPP _0
sFileName = value; M7ers|&{
} 0PU8#2pR
([-|}
Z^]|o<.<I
public int getNSplitter() DyeQJ7p
{ @J5Jpt*IE
return nSplitter; <$F\Nk|x
} yY[<0|o u
cx}Q2S
s<9RKfm
public void setNSplitter(int nCount) p98~&\QT
{ 4hAl-8~Q6
nSplitter = nCount; O!Oumw,$
} 6KVnnK
} ;9~6_@,@o
mp9{m`Jb*
G:pEE:W[
/* U$ F{nZ1
**Utility.java '@jXbN
*/ +hE(Ra#
package NetFox; hSFn8mpXT
4O;OjUI0a
_~rI+lA
public class Utility { RRGWC$>?
]J:1P`k.
1gmt2>#v%
public Utility() }~"hC3w
{ x_c7R;C
%I-+Ead0i
F B?UZ
} ;Ra+=z}>
_R.B[\r@
//线程睡眠 $<^u^q37u
public static void sleep(int nSecond) "Kc>dJ@W
{ ]S(%[|
try{ /[6j)HIS
Thread.sleep(nSecond); jS+AGE?5e
} s/7 A7![
catch(Exception e) d3W0-INL
{ K]j0_~3s
e.printStackTrace (); ,RgB$TcE
} :^Fh!br==
} oyNSh8c7c
YKE46q;J
//日志 nK$X[KrV'
public static void log(String sMsg) B*~5)}1op
{ NvHJ3>"%
System.err.println(sMsg); BWrv%7
} !2z?YZhu
: C b&v07
AgRjr"hF*e
public static void log(int sMsg) 1fo U
{ rp6q?3=g
System.err.println(sMsg); j6
} >IX/< {);M
} )r[&RGz6
hSK;V<$[Z
,oNOC3U
/* ZVbl88,(l
**TestMethod.java e]T`ot#/
*/ C=s1R;"H
package NetFox; !A>z(eIsv`
?UK|>9y}Z
lj{VL}R
public class TestMethod { o/C\d$i'
{q<03d~9|G
zOV=9"~{
public TestMethod() j:}DBk
{ ///xx/weblogic60b2_win.exe H-3Eo#b#
try{ _[Vf547vS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $8p7D?Y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); LY[~Os W
SiteFileFetch fileFetch = new SiteFileFetch(bean); xGU(n_Y
fileFetch.start(); Qc[3Fq,f
} 8E8N6
catch(Exception e){e.printStackTrace ();} !q-f9E4`
E;d7ch
@q"m5
} 25NTIzI@@
-F=v6N{
@xeAc0.^
public static void main(String[] args) iA0q_( \X
{ mo1oyQg8
new TestMethod(); nOQa_G]Gz
} zNY)'
} _{Sm k[
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