社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 8475阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* h*w9{[L  
**SiteFileFetch.java A;AQw  
*/ =NB[jQ :(  
package NetFox; *^>"  h@J  
import java.io.*; An2 >]\L  
import java.net.*;  Y@,iDQ  
mV0,T*}e  
Pz)lq2Zm9  
public class SiteFileFetch extends Thread { @]uqC~a^  
v^"\e&XL  
E@VQxB7+  
SiteInfoBean siteInfoBean = null; //文件信息Bean "Eh=@?]S_  
long[] nStartPos; //开始位置 ZL|aB886  
long[] nEndPos; //结束位置 8SRR)O[)}  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 n 0!8)Sth  
long nFileLength; //文件长度 N8A)lYT]_u  
boolean bFirst = true; //是否第一次取文件 IjI'Hx  
boolean bStop = false; //停止标志 Nd8>p.iqO  
File tmpFile; //文件下载的临时信息 8/e-?2l  
DataOutputStream output; //输出到文件的输出流 C'R9Nn'  
Dfs^W{YA  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) +n^M+ea;  
public SiteFileFetch(SiteInfoBean bean) throws IOException -()WTdIy  
{ ;m7V]h? R  
siteInfoBean = bean; zt.k Nb  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 17hoX4T  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ]545:)Q1  
if(tmpFile.exists ()) @9/I^Zk  
{ @3`5(xwzm  
bFirst = false; x0j5D  
read_nPos(); c^}G=Z1@  
} O|Uz)Y94  
else y2W+YV*  
{ OG$n C  
nStartPos = new long[bean.getNSplitter()]; `[H^ `   
nEndPos = new long[bean.getNSplitter()]; \,R;  
} _CD~5EA:  
<AgB"y@  
J[lC$X[  
Yp\n=#$[  
} s|C[{n<_  
\'|n.1Fr  
u(vZOf]jL  
public void run() 1UP {j`-K|  
{ i'f w>-0  
//获得文件长度 HZ3;2k  
//分割文件 I`_2Q:r  
//实例FileSplitterFetch 0zW*JJxV  
//启动FileSplitterFetch线程 FjCGD4x1N  
//等待子线程返回 ~5 6&!4  
try{ BU -;P  
if(bFirst) bEcs(Mc~  
{ |[],z 8  
nFileLength = getFileSize(); t/ \S9  
if(nFileLength == -1) WI\a  
{ @$ 7 GrT  
System.err.println("File Length is not known!"); kf@JEcKV  
} UL[,A+X8D  
else if(nFileLength == -2) rrL.Y&DTK  
{ (xgw';g  
System.err.println("File is not access!"); l~Jd>9DwY  
} |WB-Ng  
else l uP;P&  
{ U7WYS8  
for(int i=0;i<nStartPos.length;i++) (d4btcg  
{ xPZ>vCg  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); V$ZclV2:Ih  
} @c^ Dl  
for(int i=0;i<nEndPos.length-1;i++) #mV2VIX#Jv  
{ AM+5_'S,  
nEndPos = nStartPos[i+1]; m%0 -3c(  
} jPSVVOG  
nEndPos[nEndPos.length-1] = nFileLength; ^ ]9K>}  
} Pn!~U] A$%  
} !Cgj >=  
t:2DB)  
.B]l@E-u  
//启动子线程 xMr,\r'+  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "$(+M t^  
for(int i=0;i<nStartPos.length;i++) tWn dAM(U7  
{ !( lcUdBd  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y w0,K&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xhP~]akHN7  
nStartPos,nEndPos,i); %`F;i)Zz  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ki><~!L  
fileSplitterFetch.start(); X&9: ^$m  
} ",,#q  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZV gfrvZP  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )- W1Wtom  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >!Yuef <P  
nEndPos = " + nFileLength); t5{P'v9J  
// fileSplitterFetch[nPos.length-1].start(); ^;EhKG  
,D{7=mDVm  
tA#Pc6zBuC  
//等待子线程结束 w(@r-2D"  
//int count = 0; nJe}U#  
//是否结束while循环 6qT@M0)i  
boolean breakWhile = false; N,TV?Q5l7  
@jn&Wf?  
529b. |  
while(!bStop) -'Z Gc8)  
{ %mC@}  
write_nPos(); Om*QN]lGq  
Utility.sleep(500); m?(8T|i  
breakWhile = true; [rx9gOOa&  
E7$&:xqx  
f30J8n"k  
for(int i=0;i<nStartPos.length;i++) t^'nh 1=  
{ 2u$-(JfoS  
if(!fileSplitterFetch.bDownOver) HJ&P[zV^  
{ IHTim T?  
breakWhile = false; `O6#-<>  
break; ]c>@RXY'  
} L3{(B u  
} P}4&J ^  
if(breakWhile) |mt W)  
break; ?L }>9$"  
egu{}5  
`4*I1WZW  
//count++; S1$^ _S =  
//if(count>4) l>\EkUT  
// siteStop(); Xmr}$<<=  
} FQ>$Ps*a[  
m4m-JD|v  
*duG/?>P  
System.err.println("文件下载结束!"); 7 z    
} ]({ -vG\m  
catch(Exception e){e.printStackTrace ();} SRfh{u  
} QVjHGY*R  
=n,;S W  
eC5*Q=ai,  
//获得文件长度 :[<Y#EX.  
public long getFileSize() _s;y0$O  
{ ^8&}Nk[j  
int nFileLength = -1; 0~U0s3  
try{ =%|`gZ  
URL url = new URL(siteInfoBean.getSSiteURL()); wNi%u{T  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P|Aac,nE+^  
httpConnection.setRequestProperty("User-Agent","NetFox"); ,g?ny<#o  
2BC!,e$Z  
=b%f@x_U1  
int responseCode=httpConnection.getResponseCode(); ]\yB,  
if(responseCode>=400) \oPe" k=  
{ Qm[((6}  
processErrorCode(responseCode); 9i\}^ s2  
return -2; //-2 represent access is error |it*w\+M  
} k*A(7qQA`4  
QjLU@?&  
"[ LUv5  
String sHeader; h.tj8O1  
^X&`YXjuN  
$R}C(k ;?  
for(int i=1;;i++) oVw4M2!"K  
{ {APfSD_4  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U)kyq  
//Utility.log(in.readLine()); 4&NB xe  
sHeader=httpConnection.getHeaderFieldKey(i); SL uQv?R}9  
if(sHeader!=null) Qb@j8Xa4[  
{ DAq H  
if(sHeader.equals("Content-Length")) W^elzN(  
{ Q3>qT84  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r^"o!,H9q  
break; :fmV||Q  
} MLr L"I"  
} .g/!u(iy  
else VQ!4( <XD  
break; ^:?z7m  
} No\#N/1@P  
} 9y\nO)\Tv  
catch(IOException e){e.printStackTrace ();} s-*N_Dv  
catch(Exception e){e.printStackTrace ();} }|h-=T '  
@d Qr^'h  
:C;fEJN  
Utility.log(nFileLength); +]t9kr  
[vtDtwL  
p3fV w]N  
return nFileLength; ,dba:D= l  
} NZ`6iK-V_  
vasw@Uto)  
[ 2@Lc3<  
//保存下载信息(文件指针位置) 0D:uM$ i]  
private void write_nPos() ' Sd&I:?  
{ I-.? qcy~  
try{ [9?]|4  
output = new DataOutputStream(new FileOutputStream(tmpFile)); yq3"VFh3d  
output.writeInt(nStartPos.length); &\?{%xj  
for(int i=0;i<nStartPos.length;i++) :%Z)u:~':  
{ j,,#B4b  
// output.writeLong(nPos); $.DD^ "9  
output.writeLong(fileSplitterFetch.nStartPos); "~C \Z} ;  
output.writeLong(fileSplitterFetch.nEndPos); BvlY\^  
} 6:r1^q6A9L  
output.close(); /x-tl)(s=  
} ICoZ<;p  
catch(IOException e){e.printStackTrace ();} FlS)m`  
catch(Exception e){e.printStackTrace ();} #oGvxc7  
} -NG9?sI\U  
=L$RY2S"  
+ $~HRbo  
//读取保存的下载信息(文件指针位置) K6<1&  
private void read_nPos() #l2WRw_t  
{ Vfw +m1sS  
try{ f2|On6/  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 'U`I  
int nCount = input.readInt(); jM@@N.  
nStartPos = new long[nCount]; 43J8PMY  
nEndPos = new long[nCount]; JvUHoc$sI  
for(int i=0;i<nStartPos.length;i++) A&'HlI% J  
{ 9.goO|~B~  
nStartPos = input.readLong(); OQX ek@~2  
nEndPos = input.readLong(); ;+qPV7Z  
} N~arxe (K  
input.close(); ,KibP_<%&P  
} \b88=^  
catch(IOException e){e.printStackTrace ();} 8&f"")m  
catch(Exception e){e.printStackTrace ();} I|[aa$G  
} ^_ZQf  
Z42v@?R.!W  
w_J`29uc  
private void processErrorCode(int nErrorCode) H+2J.&Ch  
{ ~pSD|WX  
System.err.println("Error Code : " + nErrorCode); b_Ky@kp  
} f4T-=` SO  
Mz{ Rh+gS  
L{CHAVkV  
//停止文件下载 TAJ9Y<  
public void siteStop() 4_I,wG@  
{ Iei4yDv ;  
bStop = true; J&:0ytG  
for(int i=0;i<nStartPos.length;i++) +TX p;6pA  
fileSplitterFetch.splitterStop(); ! xqG-rd '  
_5YL !v&  
GrQAho  
} <db/. A3  
} t_VHw'~"  
//负责部分文件的抓取 fW}H##b  
**FileSplitterFetch.java ?R{?Qv  
*/ a m zw  
package NetFox; $BBfsaJPT  
gZ!(&u  
>qUO_>  
import java.io.*; <,hBoHZSL  
import java.net.*; ?h3Ow`1G  
quUJ%F  
=L wX+c  
public class FileSplitterFetch extends Thread { YV940A-n  
o%9>elOju  
-MEz`7c~  
String sURL; //File URL Gf]s?J^a  
long nStartPos; //File Snippet Start Position Pd;ClMa%  
long nEndPos; //File Snippet End Position |f}NO~CA  
int nThreadID; //Thread's ID &lS0"`J=  
boolean bDownOver = false; //Downing is over tx1jBh:e=  
boolean bStop = false; //Stop identical z|?R=;,u`  
FileAccessI fileAccessI = null; //File Access interface I2DmM"-|  
7VXeu+-P  
8k`zMT  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !^fJAtCN]  
{ ipp_?5TL  
this.sURL = sURL; pz IMj_  
this.nStartPos = nStart; C;) xjZiR  
this.nEndPos = nEnd; 0amz#VIB<u  
nThreadID = id; rlIEch^wZ  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 udZ: OU<  
} E$>e< T  
">QY'r  
QPcB_wUqu  
public void run() _Usg`ax-  
{ 85{vz|(':  
while(nStartPos < nEndPos && !bStop) )x7hhEk=^  
{ piFQ7B  
&P3vcB  
^aW[~ c  
try{ WO9/rF_  
URL url = new URL(sURL); E\S&} K,s  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NFc8"7Mz}  
httpConnection.setRequestProperty("User-Agent","NetFox"); r*wKYb  
String sProperty = "bytes="+nStartPos+"-"; !~l%6Z5  
httpConnection.setRequestProperty("RANGE",sProperty); z.^ )r  
Utility.log(sProperty); ~QcKW<bz  
%nh'F6bNgv  
X8x>oV;8  
InputStream input = httpConnection.getInputStream(); 0cUt"(]  
//logResponseHead(httpConnection); ]c2| m}I{:  
3T/j5m}+!  
( `+Z'Y  
byte[] b = new byte[1024]; ,GnU]f  
int nRead; 3p W MS&  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;/T-rVND  
{ UYOn p7R<  
nStartPos += fileAccessI.write(b,0,nRead); 2oG|l!C  
//if(nThreadID == 1) hFfaaB  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); se HbwO3 b  
} *KH@u  
T6roz  
DZ.trtK  
Utility.log("Thread " + nThreadID + " is over!"); [Mc5N  
bDownOver = true; =+S3S{\CK  
//nPos = fileAccessI.write (b,0,nRead); 9nS!  
} am+mXb  
catch(Exception e){e.printStackTrace ();} Jk`)`94 I  
} D#1~]d  
} m@u`$rOh  
UiZp -Y%ki  
D])YP0|}  
//打印回应的头信息 ld}$Tsy0  
public void logResponseHead(HttpURLConnection con) (x0*(*A}  
{ 8I0T u  
for(int i=1;;i++) gCr|e}w-  
{ E2H<{Q   
String header=con.getHeaderFieldKey(i); O:tX0<6  
if(header!=null) ko2j|*D6@~  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 89#0vG7m  
Utility.log(header+" : "+con.getHeaderField(header)); 6n\z53Mk  
else /JubiLEK  
break; fR%1FXpK&  
} Wd56B+  
} SuH.lCF-g  
yL x .#kx6  
*3`oU\r  
public void splitterStop() G? gXK W  
{ ~!:Sp_y  
bStop = true; ~uR6z//%  
} 56SS >b  
_pko]F|()  
i(yAmo9h  
} L\wpS1L(  
5YI/Ec  
F0'A/T'ht  
/* "E)++\JL  
**FileAccess.java AYA&&b  
*//文件访问(定位,写) Oqpl2Y"/  
package NetFox; A9l})_~i  
import java.io.*; \y H3Y  
' q<EZ {  
Hn9F gul&  
public class FileAccessI implements Serializable{ G9n /S=R?  
jXY;V3l  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SAG` ^t  
RandomAccessFile oSavedFile; (21 W6  
long nPos; tdnXPxn[  
2iPmCG  
mk%"G=w  
public FileAccessI() throws IOException Ly)(_Tp@+  
{ nJ*mEB  
this("",0); Z#F,y)YiO  
} (!VMnLlXRK  
-<51CDw,  
MO~~=]Y'  
public FileAccessI(String sName,long nPos) throws IOException }>;ht5/i/  
{ ..q63dr  
oSavedFile = new RandomAccessFile(sName,"rw"); 6/mkJj+"  
this.nPos = nPos; <cDKGd  
oSavedFile.seek(nPos); B]|6`UfB  
} 6i]Nr@1C  
Ac[|MBaF  
1J-Qh<Q   
public synchronized int write(byte[] b,int nStart,int nLen) oF;%^XFp  
{ fys5-1@-p  
int n = -1; xi?P(s A  
try{ r}oURy,5  
oSavedFile.write(b,nStart,nLen); WjY{rM,K  
n = nLen; bvip bf[m<  
} 0Oc}rRH(C  
catch(IOException e) ~IlF*Zz#}6  
{ _oJ2]f6KX  
e.printStackTrace (); F<yy>Wf  
} }{&l n  
*|LbbRu  
,C{^`Bk-W  
return n; iY ^{wi~?  
} =de<WoKnu2  
?{ B[^  
|jahpji6  
} (VYR!(17  
mW~i c  
NZo<IKD$  
/* ]{IR&{EI-  
**SiteInfoBean.java :cc[Jco@w  
*/ zBk_-'z  
package NetFox; ~~C6)N~1  
p!+L  
8^/+wa+G  
public class SiteInfoBean { ${hyNt  
@72x`&|I?u  
;".z[l*  
private String sSiteURL; //Site's URL L]k*QIn:h  
private String sFilePath; //Saved File's Path gB]C&Q  
private String sFileName; //Saved File's Name RVc)") hQj  
private int nSplitter; //Count of Splited Downloading File m_Mwg  
sA/,+aM  
$d'CBsu|<  
public SiteInfoBean() 9v~1We;{$  
{//nSplitter的缺省值为5 [O=W>l  
//default value of nSplitter is 5 r_Lu~y|  
this("","","",5); U r^YG4(  
} KHvIN}V5?3  
Uh|TDuM  
3PsxOb+  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Dba+z-3Nzy  
{ AK6=Ydu  
sSiteURL= sURL; hIR@^\?  
sFilePath = sPath; @. "q  
sFileName = sName; 7egq4gN]2Y  
this.nSplitter = nSpiltter; Q"A_bdg5  
,# ]+HS^B  
T3=(`  
} X$/E>I  
S#,+Z7  
y'^F,WTM  
public String getSSiteURL() 'r~8  
{ P"b8!k?  
return sSiteURL; C?,*U  
} !6lOIgn  
(I[s3EnhS  
\H^;'agA  
public void setSSiteURL(String value) R6 ;jY/*#  
{ }@wVW))6$  
sSiteURL = value; k!&:(]  
} &1P(O\ d  
-!l^]MU  
}7%9}2}Iw  
public String getSFilePath() OZ=Cp$  
{ (i\)|c/a7  
return sFilePath; $|k%@Q>  
} sMP:sCRC  
0 <g{ V  
`g--QR  
public void setSFilePath(String value) )T9~8p.  
{ [P{a_(  
sFilePath = value; rkq#7  
} <KX&zi<L)  
teAukE=}  
Y3k[~A7X  
public String getSFileName() n&$/Q$d&  
{ uxb:^d?D!  
return sFileName; > VP5vkv=  
} #ra*f~G  
?pqU3-knH  
~cIl$b  
public void setSFileName(String value) `Ug tvo  
{ h/HH Kn  
sFileName = value; "TNVD"RLY  
} myIe_k,F  
Cc Y7$D  
ALXTR%f  
public int getNSplitter() W qE '(  
{ f0DK>L  
return nSplitter; ^&Q< tN 7  
} B$?^wo  
QD$Gw-U-l=  
i$C-)d]  
public void setNSplitter(int nCount) s1 bU  
{  L=]p_2+  
nSplitter = nCount; u h )o  
} O%&cE*eX  
} 6]n/+[ ks  
F?BS717qS%  
0e16Ow6\!1  
/* D:9 2\l  
**Utility.java Juu+vMn1  
*/ G?xJv`"9iC  
package NetFox; Om9jtWk  
JNi=`X&A  
T<yb#ak  
public class Utility { y`S o&:1  
e;h,V(  
:$ %>4+l  
public Utility() J+ts  
{ t7*#[x)a  
sJU`u'w  
I 8z G~L%"  
} jn=:G+0  
g`[$Xi R  
//线程睡眠 o\!qcoE2W  
public static void sleep(int nSecond) rt}^4IqL  
{ 5JSrrpGr  
try{ %\6Q .V#s  
Thread.sleep(nSecond); Ej"u1F14J  
} h/m6)m.D  
catch(Exception e) !%[S49s  
{ #|f~s  
e.printStackTrace (); 6Hf,6>  
} BJy;-(JP  
} :NE/Ddgc'  
;gB`YNL  
//日志 KY.ZT2k  
public static void log(String sMsg) ,Eu?JH&}u  
{ (MLhaux-  
System.err.println(sMsg); 7lA:)a_!]  
} m3 -9b"  
/X#z*GX  
~x]9SXD%  
public static void log(int sMsg) G;1?<3   
{ 7x k|+!  
System.err.println(sMsg); ^+/kr/  
} [Qj;/  
} @R q}nq=k  
nc?B6IV  
|.U)ll(c  
/* $[ z y  
**TestMethod.java rRb+_]Lg  
*/ ^3~e/PKM  
package NetFox; | C+o;  
FHg0E++?  
c0rk<V%5+  
public class TestMethod { ^%<pJMgdF  
=RsXI&&vh  
8@\7&C(g17  
public TestMethod() [hh/1[   
{ ///xx/weblogic60b2_win.exe vHKlLl>*2  
try{ o\=n4;S  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #wR;|pN  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D4u% 6R|F  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q[u6|jRt  
fileFetch.start(); TqAPAHg  
} N4!<Xj  
catch(Exception e){e.printStackTrace ();} z`3( ,V  
MaY682}|y  
cgT  
} I4c!m_sr  
<48<86TP  
$l[Rh1z`;+  
public static void main(String[] args) 27Emm c  
{ md Gwh7/3  
new TestMethod(); EbQa?  
} EqB)sK/3  
} +j/~Af p5f  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八